Complex sentence: Williams got control of the Cadence master tapes in the 60s,but he limited releases of the Cadence material to that of himself and another former Cadence artist, Lenny Welch, to LPs that were released on Williams' current label at the time, Columbia Records.
Split into simpler sentences: Williams got control of the Cadence master tapes in the 1960s but limited releases of Cadence material to that of himself and another former Cadence artist, Lenny Welch. This material was released on Williams' current label at the time, Columbia Records.