So far I have this:
params:add_control("play", "Play", controlspec.new(0, 1, 'lin', 0, 0, ""))
params:set_action("play", function(x) reels.play(true) end)
params:add_control("rec", "REC", controlspec.new(0, 1, 'lin', 0, 0, ""))
params:set_action("rec", function(x) reels.rec(sel,true) end)
This starts playing and recording (but not select the track before, like the key3) but of cause does not stop it. I donāt know how to do that.