Complex sentence: After a good friend noticed that his later albums had changed in sound, Vince Clarke realised this had been due to his having changed from using a Roland MC-4 Microcomposer to using MIDI sequencers.
Split into simpler sentences: After a good friend noticed that his later albums had changed in sound. Vince realised this had been due to his having changed from using a Roland MC-4 Microcomposer to using MIDI sequencers.