The first commercially successfully 33-1/3 rpm long playing (LP) was released by Columbia.
June 21, 1948: Columbia's Microgroove LP Makes Albums Sound Good | This Day In Tech | Wired.com
	
		
			
		
		
	
				
			June 21, 1948: Columbia's Microgroove LP Makes Albums Sound Good | This Day In Tech | Wired.com
 
	 
  
 
		 
 
		 
 
		