Complex sentence: On March 14,1958 the RIAA certified Perry Como's hit single "Catch a Falling Star" as its first-ever gold record, and the "Oklahoma!" soundtrack was certified as the first Gold album four months later.
Split into simpler sentences: On March 14,1958 the RIAA certified its first Gold Record, Perry Como's hit single "Catch a Falling Star". The "Oklahoma!" soundtrack was certified as the first Gold album four months later.