My default license is Attribution-ShareAlike 3.0, which means that you are free to redistribute or remix the work as long as you provide attribution and release your derivative works under the same, similar, or a compatible license. Commercial use is fine, as long as the commercial use is under the same license. (But see the canonical definitions on CreativeCommons.org for the formal definition of the license).
For attribution, give my name and a link — something like “Music by Lucas Gonze (gonze.com).”
If you want to use another license, such as one which restricts commercial use, contact me. One way to do that is to submit a comment on this blog entry.
For music which I composed, the license grant applies to the composition as much as to the sound recording. For music which someone else composed, I take care to use only music which is firmly in the public domain or under a free license compatible with my grant. If there are samples the same rules apply.
There are cases when the terms stated here don’t apply, such as when I did something collaboratively and lack the rights to make these claims, when a piece of work predates this statement, or when a piece of work is in a medium (such as code) aside from music. This statement only applies when I explicitly say so.