SID Music

SID music is the term given music composed on a Commodore. SID stands for Sound Interface
Device, which is the chip in the Commodore computer that produces sound.  The SID chip has three
voices.  Because music is generally composed with four voices, it might be thought that music produced
with three voices cannot possibly come near what would be called high quality compositions.  But a
good SID arranger knows how to get around that limitation and compose music files that are full and
professional sounding.  Besides that, a second SID chip can be added which allows six voice
compositions.

Most Commodore club public domain libraries contains hundreds of music files.  So do Bulletin Board
Systems (BBS's), whether maintained by clubs or by individuals. For example, the SID area on CIVIC
64 (Ventura-Oxnard CA) BBS is sort of a music collector's paradise, containing selections gathered
from around the world via the Internet. And obviously, this latter source in the ultimate SID lover's
paradise.

In order to play SID music files, a player program is needed. There are several available for
downloading from the Internet and most BBS's, as well as in club libraries. Some of these programs
play music files only.  Others play music and, if the files are on the disk, also display words and/or a
picture.  Among these is STEREOPLAYER 8.

Most player programs look for files that have a .MUS (music) file extension following the name.  A file
with words for the music will have the same name as the music file but with a file extension of .WDS.  A
file with a picture to show while the music plays will have the same name as the music file but with a file
extension of .PIC. So, when copying music files, also copy any files with the same name that contain the
.WDS and/or .PIC extensions.

Another file extension associated with music files is .STR.  An .STR file extension refers to music
written to be played in Stereo. To sound right, music files having both the .MUS and .STR file
extensions need a cartridge like SID SYMPHONY or an additional SID chip.  The reason is because
the .MUS file contains the music for the left channel of the Stereo which the existing SID chip handles,
and the .STR file contains the music meant for the right channel which the additional SID chip handles. 
(With some slight modifications, an additional SID chip can be piggybacked onto the existing SID
chip.)

There are other music files which are "compacted" so that a single file can be sent by modem, such as
from the BBS.  This also ensures that all the files intended by the author go together.  Files with .SAL
.PIL .MSW, or .SLR extensions are compacted files and must be dissolved before the player program
can use them.  Simply load like any BASIC program and run.

An .SAL file is a sing-a-long file and it dissolves into its .MUS file and .WDS files.

A .PIL file dissolves into a .PIC file and a .MUS file.

A .MSW file dissolves into .MUS, .STR, and .WDS files.

A .SLR file when dissolved becomes .MUS, .STR, .PGG, .ANI, and .WDS files.  The .ANI extension
stands for animated picture and needs a player program that can show them.  The extensions of .PGG
and .PJJ are for compressed versions of KOALA and DOODLE art that also need special or later
versions of stereo player programs to display.

From The Civic 64/128 Gazette, via the Commodore Information Center
http://home.att.net/~rmestel/commodore.html