I understand, or at least think I understand, that the tremolo harmonica is not the first (or second, third, etc.) choice for playing the blues. That being said, I happen to be married to someone who is uninterested in the blues but more melody/folk sound and the tremolo has the sound I believe she is looking for. Any thoughts on where to go for online lessons? I have looked through YouTube, and there seems to be a lack of instruction videos (plenty of songs being played but short on how to get there).
She might consider, if she is the sort for learning keys and stuff, learning to play stacked C/C# harps. It's kind of like learning chromatic. I've given it a try and can do it on a couple very simple numbers.