At this point, I had been supporting myself by teaching private music lessons to a wide range of students, and a common problem was figuring out how to help them practice rhythm at home. I would record backing tracks for them on my guitar, but that was a tedious process and they were stuck with the tempos I recorded them at. I wanted a flexible, software-based solution.
And there were a few: Band in a Box, iReal Pro, and a couple crappier ones. But they were all some combination of a) hard to use, b) crappy-sounding, c) expensive, and d) not well-designed for the kind of music I was teaching.
Every few months, I would search for my dream product, but I always came up empty.
Eventually, I got fed up enough that I decided to take some time off the harmony-instruction project that I'd been toiling away at for over a year in order to see if I could hack something together for at least my students to use.