Complex sentence: After being very often performed in the period between the two world wars, his compositions fell into obscurity for the most part; but the 1990s witnessed a small-scale revival of his output, and an increased coverage of it on record.
Split into simpler sentences: After being very often performed in the period between the two world wars, his compositions fell into obscurity for the most part. But the 1990s witnessed a small-scale revival of his output, and an increased coverage of it on record.