With 6/8, most people either count 2 or 3 beats to the measure, which means the metronome click would correspond to either a dotted quarter (2 beats per measure, shown in the first bar of 6/8 below), or a quarter (3 beats to the measure, shown in the second bar).


For odd signatures like 5/8 or 7/8, you can either have the metronome click on every eighth note, or on every quarter note, which would mean it would take two bars for the click to cycle back around, as shown below.

Mardy, I know what you meant, but I wanted to caution you about thinking of this like triplets.

Here comes the pedantic percussionist ...

It sounds like triplets perhaps, but in 6/8, with an eighth-note playing on each beat so that you have 6 notes per bar (measure), those are not triplets and should not be called as such.

As far as the metronome issue, it depends on what you have your metronome set to. If it's clicking quarter-notes when you are in a odd meter such as 5/8, 7/8, 11/8, etc., the click will not land on beat one every other bar (see Mr. A's graphic above). If you have your metronome click the eighth-notes, then the click will be on each pulse throughout the measure.

LOL, Bart! I read that first line and felt compelled to make the same comment. Thankfully I read the whole thread first, suspecting someone beat me to it. I don't think your comment was pedantic at all. The mistake is very common and I wish more of us held each other accountable to better reading.