A song? or a number, a track, a cover, a single,...

• Why persist in calling them NUMBERS when mp3 audio/mp4 video files are truly random access?
  The ordinal position or index number of the song in a sequential order on the medium is no longer relevant.
  We don’t use gramophone records any more!
  


• Why persist in calling them TRACKS when when we have discontinued the use of tape, gramophone records and even compact discs?
  Today songs are merely streams of bits in files on a random-access flash memory!!
  


• Why persist in calling them COVERS when there aren’t racist white cover versions and black versions of songs anymore?
  


• Why persist in calling them SINGLES when the era of the 45 rpm single song per side vinyl gramophone record is long past?

Sociological artifacts of a culture long past?
Just call a song a song, for that's all it is.

08:37 +0530 Wed. 08-Jan-2014
So, in the present context, language terminology like
NUMBER, TRACK and SINGLE are no longer meaningful descriptors for SONGS.
Those terms had meaning in the age of gramophone records, tapes and CDs, which are no longer used -- so those terms are neither relevant nor meaningful.

Today, we live in the age of network uploaded/downloaded digital multimedia files in mp3 and mp4/flv random-access formats, stored on flash memory devices and computer memory drives.
We share (identical to the original) digital copies of songs over the Internet.

As far as the term COVER is concerned, the politics of radio-transmitter stations which stimulated the need for a “cover” no longer exists.

The term is now misused for example: for Anu Malik composing and Shankar Mahadevan singing a “cover” for an originally Nusrat Fateh Ali Khan number. Nusrat Fateh Ali Khan of Pakistan sang the Sufi religious qawwali “allah-hoo allah-hoo allah-hoo”.
This was re-composed as a cover “I love you, I love you, I love you” by Anu Malik and sung by Shankar Mahadevan for the movie, Auzaar(1992).