Complex sentence: Another milestone was a television recording of Puccini's Tosca for television and starring internationally known baritone, Tito Gobbi in addition to two antipodean singers, the soprano Marie Collier and tenor, Donald Smith.
Split into simpler sentences: Another milestone was a television recording of Puccini's Tosca for broadcasting. This starred internationally known baritone, Tito Gobbi in addition to two antipodean singers, the soprano Marie Collier and tenor, Donald Smith.