Starting next week - we will be posting some viable workflows on how to use the Montage as a Performance Recorder - for capturing your ideas and how to export them and go about building the idea into a finished composition....

Hi I have bought the new yamaha montage 8.I have a small clarification.When I record ,I am not able to add tracks over the existing recording.OR in montage, is it only possible to record one voice?

There are no "voices" in Montage. All programs in the Montage are referred to as "PERFORMANCES".

The recorder in the Montage is a direct PERFORMANCE RECORDER - you recall a Performance and you can record yourself interacting with that PERFORMANCE.
Upon completion of the Recording, when you press STOP - your recording is stored to internal Memory and given a default name. You are also offered in the screen to SAVE the recording as a .MID (Standard MIDI File) for exporting it to your DAW for editing, if that is what you desire to do.

REPLACE recording will always Replace what you have recorded previously
OVERDUB will allow you add additional recording to existing recording _ if you do not select OVERDUB you simply wipe out what you have recorded.
PUNCH will let you hear up to the IN point, then it will Replace what you have recorded up until the OUT point.

All tracks go into record with the Direct Performance Recorder.

It is unclear from your post what exactly you were attempting to do. (But it sounds like you had REPLACE record selected. If you want to add additional tracks to a SONG - you must use OVERDUB record).

Please check in during the week for some ideas on workflows with the Direct Performance Recorder.