GUI tweaks to make rounds easier to understand

[jeffkaufman]

Jed's suggestions:

• Have a switch or checkbox for rounds vs non-rounds. Among other things, that might make it easier for non-round people to ignore the rounds use case.

• In rounds mode, provide a selectable option that would make just the leader repeat on every part. The reason I suggest this is that we can currently do either of two things: (1) have everyone on every part; or (2) have everyone on only one part. (…or (3) have everyone on every other part or something, but that seems like it’s rarely something we would want to do.) I feel like option 2 is often what we want, and option 1 is sometimes what we want if there are only three or four singers, but usually what we want is a different option, call it (4), where the lead singer is on every part (providing an anchor for each part) and everyone else is only on one part. If I understand the back end right, I feel like that wouldn’t be too hard to implement—you could just set the Repeat number differently for the person in bucket 1 than for the people in the other buckets. But I may be wrong about that.

• Instead of having a text box for the number of repeats, just have boxes for the number of parts and the number of beats per part, and then let the user select which of the above behaviors you want (options 1, 2, or 4—though probably in the opposite order, because I feel like option 4 should be the default). Then have the system determine the number of repeats automatically, based on the selections. In other words, provide a GUI that shows things in terms of the way that the singers are thinking about it, rather than in terms of how the implementation works. (You could still have a Repeats text box if you want to allow people to manually enter a number there, to get unusual effects like option 3 above; but maybe that text box could be hidden in some way so that it wouldn’t be the main GUI that people would use.)

Filed #239 for the functionality needed to support the "only the leader repeats" part