Serenade

[Tanya Shivari]

Music sung or performed in the open air at nights; --
usually applied to musical entertainments given in the open air at
night, especially by gentlemen, in a spirit of gallantry, under the
windows of ladies.

[Cami]

perfrom a [complimentary] vocal or [instrumental] [piece] of music.

[Tanya Shivari]

when fraternities come to sing little songs to the girls at [sorority] houses. This usually happens during pledgeship and the new members are the ones doing the singing. The boys will often change words of popular songs to [suit] the sorority/school and have to be [dressed up].

[Gregory]

A piece of music sung or played in the open air, typically by a man at night under the window of his beloved.

[Monty]

to play a piece of music or sing for someone, especially for a woman while standing outside her house at night: