1.78s: (c. 1900 - 1960)
The first disc format was the 10-inch 78 rpm record, pictured above in the center,invented around 1900. The first record player was invented around 1870 by Thomas Edison,but this used cylindrical records about the size of an empty toilet paper tube. The flat78s were much easier to store. The grooves on these records were much larger than laterLPs and 45s (about 4 times as big) and the needles were larger too. 78s were recorded andplayed back 'acoustically', without any electric amplifiers or microphones,until about 1925. 78s were obsolete by about 1960. Since the grooves are so spaced out andthe records spin so fast, a standard 10-inch 78 can't hold more than about 3 minutes ofmusic per side. They are typically made of a shellac compound (as in furniture finish!),and have the consistency of a china plate, so they are very thick and heavy and breakeasily.
33s / 'LPs': (c. 1948 - 1990)
The 33, a.k.a. the 'LP' (Long Playing record) or 'album', picturedabove at left, was invented in 1948. These LPs were popular until around 1990 when CDswere popular enough to take over. An LP could hold up to a total of 60 minutes of music,but most didn't have more than 40 minutes. They are made of vinyl plastic rather thanshellac, so they are more flexible and don't tend to break like 78s. The grooves are 4times smaller, so they were originally called 'Microgrooves' (MG), and early LPshave this written on the label.
Interestingly enough, there are enough people still willing to buy 'classic'albums, particularly jazz and blues, that some of the labels in those styles, like BlueNote records, Original Jazz Classics (a.k.a. Prestige, Riverside, Contemporary, New Jazz,etc) and Delmark Records are once again pressing and selling LPs for about $9 - 13 throughmail order. LPs of some newer releases are available, in very limited quantities.
45s: (c. 1949 - 1990)
The 45, pictured above at right, was the alternative to the LP when you wanted to record asingle pop song rather than a full album. The 45 had the same smaller-sized groove as theLP, and the center hole was larger. 45s became popular in jukeboxes, which had previouslyused 78s, because 45s took up less space and you could fit more songs in the box. Suddenlyjukes went from offering 24 or 40 songs on 78s to having 100 to 200 songs on 45s. 45s arealso made of vinyl rather than shellac, and can hold up to about 5 minutes of music oneach side. 45s are still being made in limited quantities for jukebox operators who havenot upgraded to newer CD jukeboxes, so you can still get some of the latest releases on45.
State-by-State Recording Laws