Ahhhhh I see the magic word "overdub"... You cannot overdub tracks with the 16 track sequencer... The PSR-2000 only allows you to overdub under style recording.. That's why they're saying you select tracks 9 and 10 because these are the drum tracks for a style.. The PSR-2000's sequencer will only allow you to record once to a track and if you try to overdub the new recorded data will replace the previously recorded one.. That's one gripe I have with Yammies sequencers in their arrangers.. Even the almighty 9000 Pro doesn't allow you to overdub using the standard 16 track sequencer.. You can do overdub recording on your PSR-2000, you just have to do it under style recording.. Hope this helped

Squeak