Would you please offer some suggestions on affordable, free, and expensive soundtrack sample libraries. Not just strings, but also beats, bass lines, trippy effects, etc.

What are the most popular?
Thanks for any light you can shed!

There's not a lot of music composition talk here at DV Info. To start a conversation with film composers, I'd recommend checking out VI-Control. v.i. control forum • Board Index [ Guest ] (http://www.vi-control.net/forum/index.php)

They're more into sample libs that you can play note-for-note using MIDI, rather than loops and beats, but there's loop and beat stuff discussed there too.

FWIW, when people over there ask about cameras, I generally direct them back over here to DV Info. :)

Adobe offers large audio sample libraries as part of the Creative Cloud. I haven't experimented with this much but there seems to be a lot there.