Reel to reel tape players were invented in the 1930's. They employ open reels of tape, one reel loading onto another reel, similar to the way a film projector operates. These players also had the added benefit of being able to record onto the tape. This feature was used extensively in the recording industry for decades. The cassette tape is the modern successor to the open reel to reel player.
. More about open reel player/recorders can be found here http://www.wisegeek.com/what-is-a-reel-to-reel-tape-deck.htm.
