Complex sentence: Although Roberts had rejoined his bandmates in Firefall briefly in the 1990s, he retired from performing due to illness; although in 2010 he returned to music and released two 4-song-EPs on iTunes and launched his website.
Split into simpler sentences: Although Roberts had rejoined his bandmates in Firefall briefly in the 1990s, he has since retired from performing due to illness. In 2010 he returned to music and released two 4-song-EPs on iTunes and launched his website.