Complex sentence: The album tracks were recorded from March 1994 through August 1995; a large portion of which Gallway had produced after reuniting with Laura, and had been friends with since the mid 1960's.
Split into simpler sentences: The album tracks were recorded from March 1994 through August 1995; a large portion of which Gallway had produced after reuniting with Laura. They had been friends with since the mid 1960's.