Complex sentence: Most of the Andrews Sisters' music has been restored and released in compact disc form, yet over 300 of their original Decca recordings, a good portion of which was hit material, has yet to be released by MCA/Decca in over 50 years.
Split into simpler sentences: Most of the Andrews Sisters' music has been restored and released in compact disc form. Over 300 of their original Decca recordings, a good portion of which was hit material, has yet to be released by MCA/Decca in over 50 years.