I knew a few 7th chords... you know, basic ones like Cmaj7, Fmaj7, G7, etc. I always played them in root position (for the most part, though I knew a few inversions). But I NEVER knew I could create these sounds. I've been listening to this Bill Evans recording almost every single day for years, and a few days after receiving the fifth lesson of ProProach, I was playing some of Bill's sounds! In short, this program gets my high marks. Thanks.