Can I assume that when I play with a drum beat that's not the same BPM as the jammr metronome that others hear me in time?
No. You will be in sync only if:
1. You play at the same tempo as jammr's Beats Per Minute (BPM) setting.
2. The chord progression has the same number of beats as jammr's Beats per Interval (BPI) setting.
You can change jammr's BPM/BPI settings from the Vote menu. Others
need to vote in order for the change to become effective. Voting
ensures that no one can sabotage or disrupt the jam session by
changing the settings.
It is not necessary to play on jammr's metronome click as long as you
are playing at jammr's tempo (BPM). That means you can disable the
metronome if there is a drum pattern playing at jammr's BPM - and the
drum pattern doesn't need to start on jammr's metronome click.
Some examples of setting BPI:
If the chord progression is Am F C G in 4/4 time signature then there
are 4 bars x 4 beats/bar = 16 beats. Make sure the BPI setting is 16.
If the chord progression is a 12-bar blues in 4/4 time signature then
BPI must be 12 x 4 = 48 beats.
Usually we stick to BPI 16 because many good chord progressions need
only 4 bars. Sometimes BPI 32 is useful for fitting 8 bars of music.