original: Eastman and Kotik performed together extensively in the early to mid 1970s.
simplifications: Eastman and Kotik worked together a lot in early/mid 1970's. Eastman and Kotik performed together a lot in 1970s. Eastman and Kotik collaborated a lot in the early 1970's. Eastman and Kotik performed together in the 1970s. Eastman and Kotik performed together often in the early to mid 1970s. Eastman and Kotik performed together a lot in the early to mid 1970s. Eastman and Kotik performed together a lot in the 1970s. Eastman and Kotik performed together quite often. This took place in the early to mid 1970s. Eastman and Kotik performed widely together in the early to mid-1970s. Eastman and Kotik performed together a great deal in the early to mid 1970s,