QUOTE(chocolatedog @ Aug 8 2008, 08:11 PM)

It's not technically a song unless a voice is singing - instrumental musical works are called pieces........
Sorry Deborah - you beat me to it!!! Glad I'm not the only one who gets a little annoyed by incorrect terminology..........
QUOTE(A.U.K @ Aug 9 2008, 12:28 AM)

Bravo Deborah and Chocolatedog...I too get very irritated when people call a piece of music a Song...SONGS HAVE LYRICS...The American boards are full of this error and don't even look at you-tube the comments are extrordinary, It is staggering just how many people refer to pieces or works as SONGS...
Hmmm. I can be as pedantic as the next forumite, but . . .
. . . words can and do change their meanings with time. For a musical example, the word "Sonata" used to mean nothing more than a piece to be played, as opposed to a "cantata", a piece to be sung. If enough people over a wide enough area for a long enough period refer to pieces of music as songs (with or without words) then that will become one meaning of what a song is. It may already have happened.
In any case, for an example that owes nothing to American misuse/neologism, how about Mendelssohn's Songs without Words? No lyrics in sight, but still songs.