GuillermoRosado,
When using the SD1 normally (with the Arranger), you will have the HOLD button on (LED on). Turning this button OFF (LED off) will disable the entire accompaniment and leave just the drums on. An equivalent can be obtained when playing MIDI files too (drum and bass can be left on while everything else is mutted!).
Hope this helps.
AJ

[This message has been edited by Ketron_AJ (edited 04-25-2002).]