Most obviously, it's an "occasional" piece, such as the Serenade to Music by Ralph Vaughan Williams, which he wrote specifically for the anniversary of conductor Sir Henry Wood, but which was good enough that it's been kept in the standard choral repertoire. If a fee is offered, it can be called a "commission."
commission
composition
... is called the composer.
The first composer that comes to mind is Dmitri Shostakovich, though I'm certain there must be others.
A person who writes music is called a music composer or a songwriter. A singer-songwriter is one who writes, composes and sing their own music material.Someone who solely writes lyrics may be called a lyricist, and someone who only writes music may be called a composer.
commission
composer
composition
... is called the composer.
The first composer that comes to mind is Dmitri Shostakovich, though I'm certain there must be others.
A person who writes music is called a music composer or a songwriter. A singer-songwriter is one who writes, composes and sing their own music material.Someone who solely writes lyrics may be called a lyricist, and someone who only writes music may be called a composer.
Generally this would be called a commission, for which the composer is paid an agreed-upon amount. It could also be called an "occasional" piece. An example of the latter would be Vaughan Williams's "Serenade to Music," which was written for a celebration of the career of British conductor Sir Henry Wood, and was set to a text from Shakespeare, to be sung by sixteen singers with whom the conductor had been associated. Very often, occasional pieces are less than memorable and don't outlive the occasion for which they're written. In the case of Vaughan Williams's "Serenade," the musical worth has outlived that first performance.
A music composer is a writer of music by definition. A composer can write sung lyrics, notes and entire orchestra scores, for example.
The music is called "Placa Omondia" by Greek composer Mimis Plessas. I found it on the stock music compilation "Ren And Stimpy Production Music" (Vol. 1)
Sampling.
This is the French composer Eric Satie.
The composer of the music and lyrics is unknown.