What is IG music overlay on Facebook?

[Gone To Lunch]

My latest CD Baby statement has an item on which is new to me:

In addition to the usual track details:

Partner = Facebook;
Type = IG_MUSIC_OVERLAY.

Qty = 50
Unit = $0.00120000

What is a IG music overlay? Adding audio to a home made video clip or some such?

Anything to do with Instagram, and is it part of Facebook?

We signed the blanket license option with CD Baby, seven years ago, which presumably now includes Instagram/Facebook?

[Drew Stephenson]

Yep, I think it's the music people can add to their instagram stories, and yes, instagram is part of facebook.
That is the full extent of my knowledge.