Sol

The name "Sol" (pronounced with a short-O, not a long-O) is the proper name for
Earth's sun, but english-speaking people rarely call it that.
English-speaking people usually call Sol "the sun", but,
any star that has one or more planets revolving around it is the sun of those planets.
The name "Sol" is officially used as the name of Earth's sun in several languages,
including Spanish, Catalan, Portuguese, Swedish, and Danish.

Sol, when pronounced with a long-O, is the fifth note of the modern musical scale.