I'm looking for some music for my horn quartet. I own the German green books and also the orange ones, but more music of all styles like marches, polkas and also classical horn quartets would be nice to have and to play to have more possibilities for gigs. Is there anything like the green books for trumpet or trombone? Or anything for brass quartet that's entertaining.

I'd be happy for any kind of ideas and suggestions, no matter which level, which style, key or transposition :-)

Hello Hornomat,
Have a look at some of the items I've composed for horn quartet (plus for solo horn and piano/orchestra)...don't forget, they're free on 8notes.
Best wishes,
Stephen Lines

It's not exactly what you're looking for, but if you haven't heard of the Fripperies, give them a look on YouTube. They're very whimsical and fun to play. The publisher's website is hornistsnest.net