So, if they want to play a concert Bb scale, they start on a C (they have to think up a whole step). Concert C is their D, Concert Ab is their Bb. Alto and baritone saxes, alto clarinet and most alto horns are Eb instruments: when they play a C it sounds like a Eb on the piano.
In addition to his feature film credits, Diaz is well-known for his many seasons on Showtime's award-winning series Weeds, where he plays the role of Guillermo, as well as his comedic performances on Chappelle's Show for Comedy Central.
The cast of Weeds during Season 2, Left to Right: Romany Malco, Tonye Patano, Mary-Louise Parker, Kevin Nealon, Elizabeth Perkins, and Justin Kirk.