I love this list of Songs About Brothers. Pearl Jam and Alice in Chains get mentions.
What Slayde Says by nomeansno. But it may not convey the mood you’re looking for.
Brothers, Philly style.
The Band’s “The Night They Drove Old Dixie Down” has lyrics in which one brother describes the death of another during the Civil War:
I always thought that Don McLean’s “Vincent,” about Vincent Van Gogh, is worded as if sung by his beloved brother Theo, although it doesn’t say that explicitly:
It isn’t about brothers, but the song ‘PS you rock my world’ is fairly good. It was written by the singer after his sister died.
There is only one non-live copy on youtube, and the acoustics are terrible though.
Brother, Brother, Carole King
Use Me, Bill Withers “My brother sit me right down and he talked to me…”