Complex sentence: In his early teens, performing under his given surname, "McIntosh", he was playing guitar in a band called "The Classics", with recurring engagements at the Hideaway Lounge in Hamilton, Ohio.
Split into simpler sentences: In his early teens, still using his given surname, "McIntosh", he was the guitarist in a band called "The Classics". They had recurring engagements at the Hideaway Lounge in Hamilton, Ohio.