Complex sentence: However, none were commercially successful in the midst of the Beatles-led British Invasion and many weren't released until Ace Records (UK) acquired Mack's original master recording tapes in the late 1990s.
Split into simpler sentences: However, none were commercially successful in the midst of the Beatles-led British Invasion. Many weren't released until Ace Records (UK) acquired Mack's original master recording tapes in the late 1990s.