Answer: As a result
Step-by-step explanation:
The correct transition to the sentence that's described in the question will be "As a result".
It should be noted that "As a result” is usually used as conjunctive adverbial phrase and it shows the cause-and-effect relationships. It functions thesame way as "Therefore" or "Hence".
Based on the information given, the answer will be "As a result, Glass started composing minimalist compositions with repetitive rhythms".