Seventy years ago this week something important happened in music history: the first LP, or long-playing vinyl record, was introduced.

At the time, the LP was a new kind of record that let people listen to longer pieces of music. And it changed the way people listened to music.

Columbia Records first introduced the LP in 1948. To celebrate this year’s anniversary, the British music company HMV and the music company Sony Classical recreated 500 copies of the first performance recorded to an LP.

The recording was of a piece of classical music: Mendelssohn’s Concerto in E minor. Violinist Nathan Milstein performed the music with the New York Philharmonic Symphony Orchestra.

All the copies of the LP are to be given away to fans, except for one, which will be donated to the British Library.

The record adds to the library’s collection of 250,000 LPs, most of which were released in Britain. The museum has other musical artifacts going back to the beginning of sound recording. These include wax cylinders, created by Thomas Edison in 1877. They were the first way fans could buy music to listen to at home.

Andy Linehan is a curator of popular music in the British library, who received the new LP donation.

“The fact that the long-playing record came into existence was a huge step for music sound recording and for the listener,” Linehan said.

He added, “Previously you could only get 3 minutes or so onto one side of a record and now because you had a narrower groove and a slower speed, you could get up to 20 minutes, which meant...you could get a whole package of songs together on one record.”

This week’s anniversary comes at a time when vinyl records have started to become popular again. In Britain, vinyl records are only 7 percent of album sales, but they are popular with fans of all ages.

The British Phonographic Industry, or BPI, says that vinyl LP sales rose to 4.1 million last year from 205,292 in 2007.

Gennaro Castaldo is communications director for BPI. He said: “Vinyl is popular because people see it more as an artifact rather than a utility.” He said that people love the tradition of buying records and then playing them at home.

He added, “The sound quality is much warmer, richer and people appreciate that.”

Rock music is still the best-selling kind of music for vinyl records. Last year, the biggest selling LP in Britain was Ed Sheeran’s “Divide” album. Older LPs, such as Amy Winehouse’s “Back To Black” and Fleetwood Mac’s “Rumours,” were also in the top 10.

Simon Winter heads public relations and events for HMV. He said the LP business is growing.

“Our record stores are stocking more vinyl than we’ve ever stocked in terms of the last 10 years,” Winter said.