No problem. Yes, just like fills, I feel no later than just before beat 4 (if 4/4) is generally the latest you can guarantee everything’s going to work.
Don’t forget, you HAVE to get back to actually playing the chords before the looper starts recording. If a chord is playing from before you hit record, the looper doesn’t ’catch’ it, because you didn’t play it while in record. So if the end of the loop isn’t the same chord, when the loop repeats it will continue to play the chord at the end until it gets to the chord you first actually played!
So, although you possibly COULD go later than on beat 4 to hit Record, you run the risk of not getting back to playing before the ‘one’…
Obviously, not such a big deal if you are recording loops to use later, and are slowing down the tempo, but if you’re using it live at full tempo, it’s a good habit to get into being consistent as to what beat you go hit Record on. One less thing to worry about!
If you are a pianist/singer, you can usually lay down a really good loop while you accompany your vocal for the verse and chorus, or head if jazz. You’ll tend to play the correct inversions etc, and just be fairly basic. Then you can hit Play, have the chords played for you and start to stretch a bit, reharmonize a bit, etc..
But a pretty cool trick is to turn BassInversion off while you record the loop (if it’s a song that doesn’t really use inversions much) and actually PLAY other inversions by changing up your LH. The accompaniment will still sound ‘normal’, but then, on one of the repeats of the loop, turn on the BassInv feature, and the whole flavor of the song will change without you having to go back to playing the chords. And with BassInv tasked to a footswitch, you can even do it just in certain spots, differently each repeat.
Another cool looper trick is to lay the loop down only with open 5th (no 3rd) chords, then you can substitute all kinds of different voicings without clashing with the accompaniment. It’s especially effective with modern light rock styles (lots of open 9th chords in today’s rock) and gives you tons of room to reharmonize and play alternate changes…
If you’ve never really played with a band and would like a taste of what it entails, record the loop for a song or a verse/chorus structure, then turn off all the arranger parts other than bass drums and rhythm guitar. Now try to fill in your comp and all the horn or string or synth parts live. That’s what you have to do in a live band! Practice this enough, next time you get to sit in with a band, you are better prepared to do more than just play the piano or organ part…
Get creative with your looper!
An arranger is just a tool. What matters is what you build with it..!