Complex sentence: After self-producing its 1999 album "Sugar" and releasing its third album "Head on Straight" in 2002, the band went on hiatus beginning in 2004 while its members pursued other musical endeavors.
Split into simpler sentences: After self-producing its 1999 album "Sugar", Tonic released its third album "Head on Straight" in 2002. The band then went on hiatus beginning in 2004 while its members pursued other musical endeavors.