this tip might be a bit basic..
but may elude some people.
when working on a beat pattern in redrum
to add different patterns is really easy
with the redrum clicked/selected
simply select one of the pattern slots (1 through 8 for whatever current letter bank, 8 x 4 = 32 patterns)
write in your pattern rhythm
and then u can press cmd-c and it will copy this pattern
which u can copy to another pattern slot by pressing cmd-v to paste the pattern
then once your patterns are set up..
theres two other ways u can do things
u can draw in your pattern changes with the pencil tool but this is kind of a pain in the ass
its much easier to just press record and press the pattern change as the track is playing and it will automatically
record the pattern changes.. ('snapped' to the length of the pattern)
another way to do this is to map the pattern changes to buttons/pads/keys either on a midi controller or the keyboard itself
u can press the bar changes as the tracks playing and it will record the pattern changes
but of course u can just click the little button on the redrum with the mouse which is just as easy..
but u have to do this as the track is playing in record mode
using the piano keys can be confusing.. and problematic because this maps globally and u will later be on a different track and trigger a pattern change when u had meant to play some keys..