Today is Vinyl Record Day, commemorating August 12, 1877; the day Thomas Edison invented the phonograph. The first disc recordings for phonographs were commercially marketed in 1895, and gradually overtook the earlier phonograph cylinder as the dominant medium of recorded sound by the 1910s, as they were more economical to produce, less fragile, and easier to store.

Records store information by encoding it in fine variations in the edges of the groove. The variations cause a stylus (needle) placed in it to vibrate at acoustic frequencies when the disc is rotated at the correct speed. Stereo records have information on both sides of the groove, while mono records have it on only one side.

Early records were made of many various materials, including hard rubber. But in the early 20th century such materials were largely replaced by a rather brittle formula known as "shellac", actually a mixture of resin and cotton or other fiber. The mass production of shellac records began in 1898 in Hanover, Germany. Shellac was the most common form of record until about 1950, when “vinyl” became the standard. Vinyl is actually transparent polyvinyl chloride (PVC), with carbon black added to increase its strength and make it opaque.

Early speeds of rotation varied widely, but by 1910 records rotating at or about 78 or 80 times in one minute became standard, with 78 rpm becoming the standard in the late 1920s. This gave a common name for such records as “78”s, although this term did not really come into use until after World War II, when a need developed to distinguish the 10-inch 78 from other newer disc record formats being produced. After WWII, two new competing formats came on to the market and gradually replaced the standard 78: the 12-inch 33-and-a-third rpm (often just referred to as the 33 rpm), and the 7-inch 45 rpm. The 33 rpm LP (for "long play") format was developed by Columbia Records in 1948 (the term “LP” was actually a trademark of Columbia, until it was adopted into common use). RCA Victor developed the 45 rpm format and marketed it in 1949, in response to Columbia.

Starting in the 1980s, vinyl records were gradually replaced in mainstream music consumer markets with the compact disc (CD). The CD is basically a digital re-engineering of the phonograph record, using digital codes instead of analog information to encode the music, and a non-contact infrared laser sensor instead of a needle. Because of the one-sided technology of the CD, the distinction between "sides" of an album ceased to exist on CD recordings. However, the basic idea of a disk with a spiral groove containing music tracks remained the same.

Vinyl records continue to be manufactured and sold today, although it is considered to be a niche market comprised of audiophiles, collectors, and DJs. Punk and hardcore bands also often produce their albums.

Top 10 rarest records:
Chances are slim that you will find one of these rare records at a flea market or garage sale, but as all vinyl record collectors know, it is the hunt that is one of the most satisfying elements of the hobby....you never know. However, the records listed here are the rarest of the rare, and in some cases there may be just a handful of copies around; or even just one.

1. John Lennon & Yoko Ono – Double Fantasy (Geffen US Album, 1980). Note: Autographed by Lennon five hours before Mark David Chapman assassinated him. Value: $525,000

2. The Quarrymen (early Beatles) – “That’ll Be the Day”/”In Spite Of All The Danger” (UK 78 RPM, Acetate in plain sleeve, 1958). Note: Only one copy made. Value: $180,000

3. The Beatles – Yesterday and Today (Capitol, US Album in ‘butcher’ sleeve, 1966). Value: $38,500, though more typically prices range from $150-$7500

4. Bob Dylan – The Freewheelin’ Bob Dylan (CBS, US album, stereo 1963 featuring 4 tracks that were deleted from all subsequent releases). Value: $35,000

5. Long Cleve Reed & Little Harvey Hull – “Original Stack O’Lee Blues” (Black Patti, US 78 RPM in plain sleeve, 1927). Value: $30,000

6. Frank Wilson – “Do I Love You?” (Tamla Motown, US 7” 45 RPM in plain sleeve, 1965). Value: $30,000

7. Velvet Underground & Nico – The Velvet Underground and Nico (US Album Acetate, in plain sleeve, 1966 with alternate versions of tracks on the official release). Value: $25,200

8. Elvis Presley - Stay Away, Joe (US, RCA Victor UNRM-9408, 1967). Note: One-sided promotional album. Value: $25,000

9. The Five Sharps - “Stormy Weather” (US, Jubilee 5104, 78 RPM, 1953). Value: $25,000

10. The Hornets - “I Can’t Believe” (US, States 127, 78 RPM, 1953). Value: $25,000