Complex sentence: Today, Alberti is regarded as a very minor composer, and none of his works are played or recorded with any regularity, but Alberti bass was used by many later composers, and became an important element in much keyboard music of the Classical music era.
Split into simpler sentences: Today, Alberti is regarded as a minor composer, and his works are played or recorded only irregularly. The Alberti bass was used by many later composers, and it became an important element in much keyboard music of the Classical music era.