why are pop songs always 3 1/2 minutes long?

When recorded media was first introduced, it was a novelty. The Edison Cylider, being the first practical distribution method for recorded sound, never took off.

The 78 rpm record did take off, and thanks to its limitations, pop songs have been limited to about 3:30 in length. You couldn’t fit more than that onto a 78. Record executives, engineers, and producers all knew this. To sell popular music, a song had to fit on one side of a 78.

Musical forms and structures evolved quickly to fill the 3:30 time limit. The verse-chorus-verse formula that still exists today came about so that songs could come to a satisfying conclusion within the time limit of the record.

These limitations were ingrained upon songwriters and arrangers for 40 years.

As technology eliminated the 3:30 barrier for popular music with the LP record and more recently the CD, I often wonder why the time limit remains. I guess old habits are hard to break.

I leave you with a ghost from the past — the original cassette tape format that survived for eight years. I have never seen one of these or even met a person that has heard of this, so don’t expect people to care about your damn ipod 40 years from now.