Syncronization Question

[loginame]

Hi,

Is it possible to syncronize "auto acompaniment style" on say a yamaha dgx-505 to a midi clock on say protools Le 6.4?

Here's the rundown:

When I record an auto acompaniment style at say 90bpm (metronome on yamaha) to an audio track in protools, and then record my own piano playing to a midi track at 90bpm (tempo on protools), the audio beat gradually gets ahead of the midi bars.

Any help appreciated.