Complex sentence: The band was formed in 2004 by Rory Attwell and Sam Mehran, and later joined by Devonte Hynes, who was originally invited to fill in at a performance in Brighton, England and afterward became a permanent member of the band.
Split into simpler sentences: The band was formed in 2004 by Rory Attwell and Sam Mehran. They were later joined by Devonte Hynes, who was originally invited to fill in at a performance in Brighton, England and afterward became a permanent member of the band.