• A variety of gramophone records exist beyond the well-known 7- and 12-inch singles.record image by Pefkos from Fotolia.com
  
  The gramophone record in the form of a flat grooved disc that rotates on a turntable was invented in 1888 but only became popular once the patent expired 30 years later. It became the most popular medium for recorded music until the emergence of the compact disc, but remains popular with some music fans who believe it offers a more nuanced sound and is more collectible. A variety of gramophone records exist beyond the well-known 7-inch single and 12-inch album. These include records that play at unusual speeds, records made of an unconventional material for easier distribution, records that play tracks at random for comedic or entertainment purposes and records with a distinctive appearance.
  
  

Alternative Speeds

• Although most people are familiar with 45-rpm singles and 33-rpm albums, vinyl records are made that rotate at other speeds. The most common alternative is the 78-rpm record that, because it rotates much faster, contains less music for the size of the record. This speed became popular when recording engineer Fred Gaisberg adapted a sewing machine mechanism that rotated at 78 rpm for use in the music industry.
  
  Another popular speed is 16 2/3 rpm. This speed allows considerably more content on a record, which means it was often used for spoken word content such as audio books.
  
  

Flexidisc

• The flexidisc is a record made of a thin plastic that can be bent without causing serious damage. Because the flexidisc is particularly light, it was historically used mainly for distributing records in unusual ways such as through vending machines or affixed to magazine covers as a free gift for readers. In some cases computer gaming magazine gave readers a flexidisc, which they could then transfer to an audiocassette on a hi-fi system. This was a cheaper way of distributing games that were normally sold on audiocassette.
  
  

Concentric grooves

• While most records contain a single groove, it is possible to produce a disc with two or more grooves. As it is difficult for the listener to get his stylus into any one specific groove with certainty on such discs, the grooves have mainly been used for gimmick records. For example, there are records that play recordings of horse racing commentary with different conclusions on each groove, allowing people to play home gambling games where each player picks a horse.
  
  

Picture discs

• A variety of techniques exist for printing pictures or photographs on records themselves rather than have a plain black vinyl. The most common involves some combination of black vinyl, a thin sheet of paper with the image, and a clear vinyl film. In some cases the picture disc is also an unusual shape such as the logo of a band. The full 7-inch diameter circle remains in place, but with an outer rim that is shaped and not part of the playable surface. One common technique is to take a 12-inch diameter circle of vinyl and cut it down to the appropriate shape.