My brother did invite me to the concert of the Wise Guys, a German acapella group. They are one of those special groups who are able to give a cheering live show and have this special cheek-in-tongue humour in a fair amount of their songs. This is the selection that helps me keeping my mood up though, you are invited to dig further.
Jetzt ist Sommer: This was the first song I heard from them and got me interested to dig further into this band. And yes, it's true, summer is an inner feeling, not something governed by the outer world.