I would love to have a chord helper window that pops up and stays on top. The window should know what key I am in and offer me all valid/common choices for the next chord from the bar I am currently working on. But it should also present me with a complete list of chords that I can simply click on, hear and select if I like the sound.

I have a MIDI program that does this and it is incredibly useful for songwriting. It makes it almost as easy to use as having a guitar in my hands as I noodle about experimenting for the sound to a new song!

Sometimes in BIAB I will actually enter all chords in a section of the song temporarily so I can click on them and hear how they work in the current context but a dedicated feature would be so useful!