Simply using a patch change to change instruments on a Roland Sound Canvas is no longer guaranteed to get the patch you intended. There are two other areas to take into consideration now.
Firstly you need to consider which bank (or
variation) you want to use.
Each instrument can have a maximum of one hundred and twenty seven variations! However, not all banks are
currently used. Some instruments have no variations while some have as many as thirteen!
To specify which bank you want, use Control Change zero (0) with a value between zero and one hundred twenty seven. Bank zero is known as the Capital Tone, while the remainder are variations.
Secondly you need to consider which map you want to use. This map idea was introduced
with the Roland SC-88, but earlier Sound Canvas owners need to know about it so that they
can ensure their sequences play correctly when played on later Sound Canvases.
To specify which map you want, use Control Change thirty two (32) with a value indicating the desired map. Map zero will use the map selected by the button on the front of your Sound Canvas. Map one is the SC-55 map. Map two is the SC-88 map. Map three is the SC-88Pro map. Map four is the SC-8850 map. You can be sure there will be more to come!
As a side note, since the CM-64/32L synths are older synths, prior to the establishing of the Sound Canvas standard, these maps are embedded as variations within the SC-55 map. So to access these two maps, select "bank one hundred twenty six, map SC-55, patch zero through sixty three" or "bank one hundred twenty seven, map SC-55, patch zero through one hundred twenty seven".
To activate the bank and map change, you must send a Patch Change message. Changing the bank or map will not do anything until a patch change is sent. From now on, any patch changes you send will remain within the current bank and map. If you try and change to an instrument that does not exist in the current bank and map combination, the instrument will not be changed. The Sound Canvases after the SC-55 range do not "fall back" to the next lowest existing variation.
So to ensure you get the instrument you want, be sure to always specify the bank, the map and then the patch.
If you feel I need to include more detail, please let me know.
Feed back on clarity and semantics will also be greatly appreciated.
Thanks, Eddie Lotter