"When You Were Sweet Sixteen" is popular song written by James Thornton and published in 1898. Inspired and sung by the composer's wife, the ballad quickly became a hit song in vaudeville. It has a long recording history that includes numerous popular singers, has been heard on film, and is considered a standard for barbershop quartets.

This is a nearly comprehensive list of notable events in music that took place in the year 1900.