It's The Trumpet.

Today's song lives and dies by the trumpet. Monotone vocals, a chorus of party people, a contagious hand clap and that trumpet trumpet trumpet make the song. The lyrics are goofy, full of summer and sweat, fun and fear of change. The song?

Jens Lekman - A Sweet Summer's Night on Hammer Hill

And the requesite lyrics:

My heart goes like
Bumpa Bumpa Bumpa Bum
Can you feel the beat of my heart?
Bumpa Bumpa Bumpa Bum
Can you feel the beat of my heart?
Bumpa Bumpa Bumpa Bum
Oh no oh no oh no oh no oh no!