Would love the ability to control the background audio track file for a slide when needed. Similar to how you can "scrub" through a video clip (with clip progress and drag bar).
Here is the situation we have. We do mixed worship with some tracks and some live instruments. When doing tracks, we would like to be able to have the music track be the background source for the lyric slides (which DOES work). The problem we have with that, during rehearsals/practice, the only option we have is to rehearse the song from beginning to end in it's entirety, which is somewhat limiting.
For instance, many times (with live music or when we do video tracks instead), we may get a part in the middle of the song that requires some technical changes for the worship group to work on (timing, melody changes, etc) that requires us to stop, discuss the changes for that part and then retry just that part to see if the changes are going to 'work' and sound best. With live instruments, obviously, I can back up a slide or two, and the instrumentalists can pick up at the last chorus or verse and we can practice that part multiple times if needed. Same with video tracks, I can 'rewind' the video a bit and retry that particular part as many times as need or keep going.
But with audio tracks, this is not possible. If the worship leader spots a problem midway through that needs to be addressed, and we stop and discuss changes, we have to then start the track over from the beginning before we can get to the part that needs work. This may mean singing 2 minutes of the song again to get to the 1 verse or chorus that we want to focus on. This takes more time during rehearsals and also wears out the singers that need to sing the entire song over and over if it's a more difficult problem that needs to be worked out.
This problem would be eliminated and we would have much more flexibility if we could do like we would do with a video track, and just 'scrub' the music track to a point prior to the issue, and back up a lyric slide or two and pick up again like we would when we play live music or video's.