I saw an ad but didn't click on it fast enough so I don't know what song it was.

[benbetita]

What's the spotify ad with the guy playing an air piano (like air guitar but with a piano) on the hood of a car?

[tsolis18]

You can check this link here, it's a playlist with songs from Spotify ads. 

https://play.spotify.com/user/spotify_uk_/playlist/4zEFrFFJWvzl1Ojsts5nkz

If not, the song might have been composed originally for the ad.