SIDPLAYER NEWS #4 April 1986 This is the fourth news file for Sidplayer, the music system published in "All About The Commodore 64, Volume Two" by COMPUTE! Books. This news file offers many hints, tips, and suggestions on how to more easily create better sounding songs. The information presented here will be of interest to both novices and experienced users. Please keep in mind that the Sidplayer Editor is to be used only by those who have purchased Volume Two. The Editor is not a Public Domain program. This document is not intended to be a guide on how to use the Editor for people who have not purchased the book. The main part of this document consists of suggestions organized by command name. After these suggestions you will find some shorter sections that describe the symptoms of Master Composer Syndrome, encourage you to hook your computer up to a stereo, and offer some advanced techniques to ponder. TEM 1. The Editor lacks a feature to play just a given measure. Although a fast forward feature is available, it can still take a while to skip past part of a song. A faster way to skip over a part is to insert the command TEM 900 at the beginning of the part to be skipped, and then insert a TEM command for the correct tempo at the place you want to hear. When you play the song, the part to be skipped will be played even faster than is permitted by the fast forward feature, and you won't run a risk of getting a CLOBBER error (unless you use the fast forward feature as well). There are two restrictions to the use of this technique. If the part to be skipped contains thirty second notes, tempo 450 will have to be used instead. If the part uses utility durations, this technique cannot be used. 2. The tempo chart on page 285 is so handy, it may be worthwhile to photocopy the page for quick reference for when you enter a song. UTL 1. If you need to get a portamento glide that is longer than a whole note, you can always use the utility duration. This will permit a glide of any duration up to four seconds. VOL 1. It is strongly recommended that you not use volumes above level 12, except when you are using the triangle waveform which is naturally quieter. If you use volume levels above 12, especially with the pulse wave, the song may overpower the speaker on some televisions, causing the sound to be distorted, and thereby detracting from the quality of your song. Not everybody has their C64 hooked up to a nice stereo that can handle the volume. 2. You need to use the VOL command on only one voice. The master volume sets the volume for all three voices. If a VOL command is used on more than one voice at the same time, the VOL on the highest numbered voice is the one that will take effect. Usually the VOL and BMP commands are used only on voice one. 3. Be aware that a popping noise occurs when the master volume is changed by large amounts. Some people feel that the popping detracts from the song, and try to minimize the popping in their songs. To reduce the popping, try using smaller volume level changes and different positions for the volume changes. The sustain levels can also be adjusted to control the overall volume. BMP 1. As with the VOL command, use BMP in only one voice. If two voices use a BMP command at the same time, the volume will be bumped by two levels instead of one. 2. BMP can be used to fade out a song when the last measure or two are repeated. Some songs also use BMP to fade out the last note, but this creates a noticeable "stepping" effect in the volume as it changes. A better way to fade out a note is to use a long release (a large RLS value). HED and TAL 1. Remember that repeat loops cannot be nested. Be especially careful of this when you have a repeat loop that contains a phrase call, and the phrase also contains a repeat loop. 2. If at all possible, try to avoid using HED 0 for endless repetition. A song that does not end does not work very well with an autoplayer. DEF 1. Some songs contain several phrase definitions right at the beginning of each voice, which often set up waveforms and envelopes that are not used until later in the song. This may be convenient but it is not always a good practice. When Sidplayer has to process several commands before the first note, the chance of getting a CLOBBER error is increased. This error occurs when too many commands are placed between notes, and they cannot all be processed in one jiffy (one sixtieth of a second). The intended way for a phrase to be used is to define the phrase as it is played the first time, and then to call it when it needs to be played again later. See pages 300 to 304 for a complete explanation of phrases. F-M and FLT 1. Sometimes it can be handy when editing a song to play only one voice at a time. Unfortunately, this cannot be done if the voice contains a call to a phrase defined in a voice that is not being played. A way to get around this limitation is to play the voice that contains the phrase definition but to include the commands F-M N and FLT Y at the beginning of the voice. Selecting a filter mode of N (no mode) and passing the voice through the filter makes the voice inaudible. This allows you to play the voice so that the phrase gets defined, without hearing the voice itself. F-X 1. In addition to generating tones for music, the SID chip also picks up a lot of the "noise" from the circuitry inside the computer. This undesirable background noise can be significantly reduced on some computers by turning on the external filter input. To take advantage of this, just include an F-X Y command at the beginning of each song you create. The songs will be free of a lot of the background hiss when played. Other than making the song sound much cleaner, enabling the external filter input will not have any effect on the song. ATK 1. It is not always desirable to use a value of 0 for the ATK command. When all three voices have an attack rate of 0, and all three voices start playing new notes at the same time, sometimes the SID chip will not gate (start playing) the notes together, and one note will noticeably start to sound before the others. The phenomenon is sporadic, but does not occur with slower attack rates, so you can use ATK 1 to get around the problem. DCY 1. To minimize the "biting" effect of the volume falling from the attack peak to a much lower sustain level, a slower decay rate can be used. SUS 1. Unfortunately, the SID chip does not provide a volume control for each voice (the VOL command affects all three voices), but to some extent, the sustain level of a voice can be used to control the volume of a voice. 2. If one voice is playing a melody and other voices are supporting it by playing harmony, it is a good idea to have the SUS level for the harmony voices set at least one level lower than the sustain level for the melody voice. If they are equal, the harmony voices can overpower the melody voice. Setting their SUS levels lower makes the melody voice stand out, and generally the song will sound a bit nicer. RLS 1. As with the ATK command, it is a good practice to avoid using the value 0 with the RLS command. A release rate of 0 sometimes makes voices cut off unevenly. It is more noticeable when the song is played on a stereo instead of a television or monitor speaker. Values from 1 to 15 are recommended for a more pleasant effect. PNT 1. The release point, set by the PNT command, determines the number of jiffies from the end of a note that the note should start to release. Always remember that the release point must be less than the duration of the note being played, or the note will not be played properly. For example, in tempo 100 a sixteenth note is 9 jiffies long. If the release point is set to 12, the note will start to release as soon as it starts playing. It will never have a chance to complete its attack, and so will not be heard, or will be hardly audible. For this reason the release point is usually set around 4 or 5. If you have the release point set larger and have to play some shorter notes, it may be necessary to temporarily set the release point smaller for those notes. You can refer to the tempo chart on page 285 to determine the exact jiffy count for any note in any tempo. 2. If notes of longer durations are being played, a reason to use a larger release point is to create a more staccato effect. 3. Setting the release point to 0 means that notes played will never be released. This is the same thing as tying the notes together. Therefore, if you need to enter a lot of notes that are all tied together, for a legato effect, set the release point to 0 instead of entering a tie for each note. 4. If a voice contains alternating notes and rests of the same duration, such as a quarter note, quarter rest, quarter note, quarter rest sequence in a bass line, a shortcut can be used. The technique is combine the notes and rests into notes of equivalent total duration and then set the release point to make the release begin where the rest would normally begin. For example, let's say that the above quarter notes and quarter rests were played in tempo 100, so each note and rest was 36 jiffies long, and the release point was set at 4. Instead of entering quarter note and quarter rest pairs, you could enter half notes and set the release point at 40, where the 40 is 36 jiffies for the quarter rest and 4 jiffies for the normal release point of the quarter note. WAV 1. For some reason, pitches played using the pulse wave in octaves 0, 1, and some of 2 sound out of tune. It may be best to avoid using the pulse waveform when playing notes in the lowest octaves. 2. The pulse waveform can be combined with the triangle waveform to create a new and useful waveform type. Just enter the number 5 (4 for pulse plus 1 for triangle) to select the WAV TP command. The resultant waveform is especially useful for harpsichord effects. 3. The waveform combination SP is much quieter and therefore is not as useful. All other combinations seem to be inaudible. 4. Don't put a WAV command right before a rest. The release of a preceding note may continue into a rest, and a waveform change before the rest may clip the end of the note and be noticeable. Instead, just put the WAV command right before the next note to be played. P-W 1. Do not use the pulse wave with a pulse width less than 100. Notes played with a width much less than 150 are inaudible on some SID chips. 2. When using the TP waveform combination, be sure to have the pulse width set below 2048. The volume of the TP waveform decreases as the pulse width goes above 2000. Also set the width below 2048 when using waveform SP. P-S 1. Pulse width sweeping works by adding the pulse sweep value to the pulse width once each jiffy. The only problem with this is that with larger sweep rates, the pulse width can exceed 4095, in which case it wraps around and starts back at 0. This causes a very noticeable popping noise which can really detract from a song. To avoid the wraparound you can use a slower sweep rate or set the pulse width lower (or higher if you are sweeping backwards). If you want to keep the same pulse width and sweep rate, first determine on which notes the wraparound occurs. These will be the notes with the longest durations. Then take each note which causes popping, divide it into two halves tied together, and insert a P-S command between them with the same sweep rate but the opposite direction. For example, if popping occurs on a half note when the sweep rate is 30, instead enter a quarter note tied to another quarter note of the same pitch, with a P-S -30 command between them. You will also need to enter a P-S 30 command after them to reset the direction of the sweep for the next note. SNC and RNG 1. Refer to pages 324 to 325 and 333 to 337 of Volume Two for the correct way to set up synchronization and ring modulation effects. VDP and VRT 1. For a more natural vibrato effect, you can change the vibrato depth while a note is playing. Just break the note into smaller notes of the same total duration, all tied together, and put VDP commands of increasing values between them. Again, remember to reset the depth back to the original value. 2. Be aware that the vibrato processing is done only for the duration of a note, and is not done when a rest is being played. When a note with a slow release rate is followed by a rest, the voice may continue to fade away during the first part of the rest. If vibrato is used on the note, it is sometimes noticeable that the vibrato all of a sudden stops as the note is fading away. To prevent this from happening, you can delete the rest, add its duration to the preceding note, and set the release point higher for that note as discussed in the above section on the PNT command. TPS 1. The SID chip cannot play pitches beyond octave 7, even when the TPS command is used. If you try to play a note above B7, the note will be played with the same pitch but in octave 7. Thus an E transposed to octave 8 will be played as an E in octave 7. To determine if a voice is being transposed out of range, watch the voice on KPLAY and see if the key goes off the right edge of the piano keyboard display and disappears. 2. It is possible for the SID chip to play pitches in octave -1 by using the TPS command with negative values, but this is rarely useful. AUX 1. When using the AUX command to change the color of the piano keys in KPLAY, do not use values outside the range of 0 to 15. Values larger than 15 do not give you any new colors, and songs using larger values may forfeit compatibility with future editions of players. MISCELLANEOUS 1. Be very careful to never let two voices using the same waveform play notes of the exact same pitch at the very same time. When this is allowed to happen, a phenomenon known as "destructive harmonic interference" can occur, which in no way damages your computer but can cause the two voices to cancel each other out and be inaudible. The effect happens randomly and is not always noticeable. The only time that two voices should simultaneously play the exact same pitches in the same octave with the same waveform is when the voices are being detuned. 2. If two notes of the same pitch are tied together, it is a good practice to put the shorter note first. This is because a note tied to another note does not release. If the longer note is put first, the release cannot begin until the shorter note starts playing, and in some cases the release would normally begin sooner. This is especially true when larger release points are used. Putting the shorter note before the longer note ensures that the release will begin at the appropriate place. 3. When a grace note is played, remember that the duration for the grace note should come out of the duration for the preceding note. This way, the note following the grace note will begin right on the beat, as it should, instead of the grace note. It may be necessary to use utility durations for both the grace note and the note preceding it. 4. KPLAY and MPLAY and the other players end a song right when the last duration is complete, even if some of the voices are not done releasing. To let each voice fade out and finish completely, it is a nice touch to put a rest after the last note in each voice. 5. Remember that when you are creating a very long song, it is much easier to break the song into parts, enter and edit each part separately, and then combine them using the MERGE utility found on page 369. This utility can also be used to create songs larger than what the Editor can hold in memory. 6. The LISTER utility on page 365, or the revised version called PRINTER which prints in three columns only to a printer, can be used to find duration bugs in songs. See SIDNEWS#1 for information on the PRINTER utility. 7. Whenever possible, please try not to use the default waveform and envelope. The default settings were chosen because they give a simple, neutral waveform and envelope which can be modified easily. Playing all three voices with the default square wave and organ-type envelope, however, can make any song, even a very good one, sound pretty blah. 8. Don't overlook the subtle but significant effects that different envelope settings can have on a song. Envelopes seem to be one of the most ignored aspects of songs. MASTER COMPOSER SYNDROME It has been observed that people who formerly used the Master Composer music system and now use Sidplayer exhibit a strong tendency to use a heavy dose of vibrato and pulse width sweeping in their songs. Presumably this is because these are two easy-to-use features that are not found on Master Composer. If you might be such a person, we urge you to control your fascination with these features and use them sparingly. Thank you! THE BASEBALL CARD PHENOMENON Some music systems may make songs sound better than other music systems, but the quality of a song depends just as much, if not more so, on the time and care taken by the person entering the song. While it is nice to have lots of songs to collect and trade, it is also important to keep the quality level high in order to maintain interest in the songs. We would prefer to encourage people to emphasize quality over quantity. SIDPLAYER ON YOUR STEREO If you don't have your computer hooked up to a stereo, you're only getting part of the story when you play a song. Playing songs over a stereo gives you fuller bass lines and triangle waveforms, and reveals other things you never knew were there. See SIDNEWS#1 for instructions on how to hook your computer up to a stereo. SOME ADVANCED TECHNIQUES TO PONDER 1. The sync mode is not used very often because it requires two voices, leaving only one voice free. The mode offers a whole variety of new tone types, however, and is definitely worth investigating. Try the sync mode with different combinations of waveforms and TPS values, as demonstrated by the song TPI#14. 2. See page 337 for a discussion of using sync and ring modulation at the same time. With this technique, you can sometimes get tones that sound like they are being filtered, even though they are not. 3. Another possibility is to use portamento with the sync mode. This is done by putting an absolute set command of a different pitch before each note that is played. When this is done on the synchronized voice which adds the harmonics, an interesting "wah" effect is produced, as in the song ETAL. 4. Some people have gotten interesting results by using the sync or ring modulation modes with nonstandard configurations. 5. Absolute set commands can be placed between rests following a note with a large RLS value to make a note slowly fade away while changing pitch. This technique was used in the song STUNTMAN. 6. A subtle technique is to use the absolute set command with detuning and portamento. Turn on the detuning and set a detuned pitch with the absolute set command. Then turn off the detuning and play a note with a slow portamento rate in effect. The note will not start at exactly the correct pitch but will move to the desired pitch. This may be useful for simulating some vocal effects. A variation on this method is to not use detuning and just use the absolute set command to set the pitch one half step below the desired pitch, with a faster portamento rate. 7. Detuning and transposition can be an interesting combination. Octave transpositions with detuning were used in PIPERS, CALLIOPE, BISTRO, and AMERICA. 8. An advanced use of detuning is to slightly detune a voice, even when it is not being played along with another voice containing the same notes, for a fuller sound. This technique is based on a principle used by barbershop quartets. 9. The POLYCON utility can be used to add a pedal effect or lingering effect (like a bell) to a song, as in FUER. This technique can also be used with fast arpeggios for another interesting effect. See SIDNEWS#3 for full instructions. 10. Detuning with polyphony also gives an interesting effect. This combination was used in the song ISLAND. 11. When the waveform TP is used, pulse width sweeping can be used to sweep the width past 2048, thereby making the volume fade out. 12. A note by note use of utility duration is very tedious but can produce some wonderful phrasing effects. See the song FUER for an example. Even using just a few carefully placed utility durations can add a nice, more natural touch to a song. 13. When two voices are playing similar notes, perhaps with different pulse widths or detuning, a very short utility duration rest can be placed at the beginning of one of the voices to create an echo effect. See the version of TAKE FIVE by Stan Halaby for an example. 14. While having only three voices can be quite a limitation, it is sometimes possible to use one voice for two different effects simultaneously. For example, CANTINA uses the same voice for both bass notes and percussion effects. The bass notes are played on the beat and the percussion effects are played on the offbeat. Phrase calls can make it easy to alternate between different waveform and envelope settings. 15. One technique to get around volume problems on a voice is to release a note before has completed its attack phase. This will require some experimentation with attack rates and release points. The technique was used in the stereo version of AXEL F. 16. A rapid succession of different pitches using white noise makes an interesting percussion line, as in the song IBEX. 17. Longer white noise notes, as in the song OSPREY, can also give an interesting effect. 18. One other interesting effect is to play a sequence of notes of the same pitch but with different pulse widths. FINAL REMARKS 1. Some of these suggestions and techniques are described in the book, along with complete instructions on how to use the Sidplayer Editor and a fairly comprehensive introduction to music theory. 2. Most people feel that it is worth $16.95 to get the complete documentation. 3. Other music systems cost twice as much and are not as well documented. 4. The book also has bitmapped graphics and sprite utilities, and sections on Advanced BASIC. 5. The Sidplayer Editor is not a Public Domain program and is supposed to be used only by those who have purchased Volume Two. If you use the Sidplayer Editor and don't have the book...