Hi Anthony, Looking through the MX manuals there doesn't seem to be a way to completely erase all the data in a performance slot. Page 54 of the MX reference manual (.pdf manual downloadable from Yamaha) describes a "JOB Initialize" function that "resets the performance parameters to their default settings". It seems to erase what's in the original performance and leave all the voices (except channel 10-drums) set as piano. It's much like a GM reset command at the start of a MIDI file. In either Performance Edit (page 45) or Part Edit (page 49) you can turn off the drum arpeggio. Be sure to store your edited performance (page 56).

There are at least 2 computer editing programs for the MX. The old Vycro MX editor can still be found on the internet if you do a search. Vycro no longer supports it, I think they released it as freeware, and you won't find it on their site (but it is hosted at some other places on the internet: run a virus check on it!). It will let you view what's in a performance on a computer and edit and save it back to the MX. And John Melas ( http://www.jmelas.gr/motif/products.php) makes an editor (see XF,/XS part of his site) that works with the MX and a demo is downloadable. Hope that helps some.