Complex sentence: Among the artifacts was a phonograph with three records, including "Rendezvous Waltz" and a 1896 recording of "Ma Onliest One" giving insight into songs being listened to during the Gold Rush.
Split into simpler sentences: Among the artifacts was a phonograph with three records, including "Rendezvous Waltz" and a 1896 recording of "Ma Onliest One". The finds gave valuable insight into songs being listened to during the Gold Rush.