Fifty years ago, electric instruments and rock bands were still in their infantile stages — everything was still being figured out.

These three albums provide a small glimpse into what was going on half a century ago and were chosen based on their innovation and lasting impact.

The Velvet Underground & Nico

Consisting of Lou Reed, John Cale, Sterling Morrison and Maureen Tucker, The Velvet Underground became known for their groundbreaking musical style. There was no point of comparison for the Velvets because their music was completely new to the world. Lou Reed, who crafted a more traditional rock sound, and John Cale, whose interest in drones and classical music background created an experimental edge, were the principal songwriters. Sterling Morrison played unique guitar solos by hitting notes during the offbeat and not always abiding by traditional scales. Also, Maureen Tucker had a distinct drumming style: she would play standing up, used cymbals infrequently and relied heavily on tom toms, the snare drum and bass drum.

The Velvet Underground & Nico was produced by Andy Warhol, who also requested Nico join the group. While nominally their producer, Warhol didn’t alter the music, thus allowing the band to craft their intended sound.

Musically, Cale’s use of drones, repetitive piano and electric viola and Reed’s use of alternate tunings, namely the Ostrich guitar style, created a unique style on their harder and more experimental tracks.

The alternate tunings would hinder people’s ability to learn their songs and the group even tuned to the drone of a refrigerator at times. Lyrically, Reed wrote many dense songs that shocked audiences due to their controversial nature, leading to it being banned from many record stores and radio stations. Aside from the grittier songs, Reed demonstrated his versatility as a songwriter with the album’s sweeter songs, namely “Sunday Morning” and “I’ll Be Your Mirror.”

Sgt. Pepper’s Lonely Hearts Club Band

Pepper’s was a musical departure from the Beatles’ previous releases, mainly by creating a more experimental and production heavy record delivered by the fictional Lonely Hearts Club Band. This idea was Paul McCartney’s, and his inspiration from the Beach Boy’s 1966 album Pet Sounds should be noted. For just as the Beach Boys had done in Pet Sounds, The Beatles incorporated more instrumentation than had been used in typical rock bands — adding French horns, saxophone, harp, brass and strings. Wilson had in turn been inspired by the Beatles’ earlier Rubber Soul, as musicians are often stimulated by each other. Beatles producer George Martin has even stated that “without Pet Sounds, Sgt. Pepper never would have happened” and that Sgt. Pepper’s “was an attempt to equal Pet Sounds.”

Pepper’s features vocal contribution from all members, with Ringo Starr and George Harrison singing one song each, and Lennon-McCartney taking lead on the rest of the tracks. The title and opening track, “Sgt. Peppers,” establishes their experimentation right away with the addition of brass instruments and a portion of an audience cheering and ends with McCartney introducing “the one and only Billy Shears” and a seamless segue into the Starr-sung track, “With a Little Help from My Friends.” Presumably, Starr’s “Lonely Hearts Club Band” analog is Billy Shears and his deeper delivery intertwined with Lennon and McCartney’s contributions in the form of questions is magnificent.

“Within You Without You,” Harrison’s contribution to Pepper’s, marks the group’s largest departure from their previous sound — almost exclusively featuring violins, cellos, various drums and Harrison’s sitar. Harrison had studied the sitar under the famous Ravi Shankar after becoming enamored with Indian music, and he was interested in incorporating it with traditional rock. “Lucy in the Sky with Diamonds,” a Lennon track, is filled with psychedelic imagery, with lines such as, “Picture yourself in a boat on a river/ With tangerine trees and marmalade skies” — with the music to match it.

Axis: Bold as Love

Jimi Hendrix amazed the world with the guitar, shocking the biggest names around, not only through sound but visually as well; Hendrix was known for playing behind his head, between his legs, lighting his guitar on fire, and playing with his teeth. Axis: Bold as Love marked an advancement in Hendrix’s ability in the studio, recording backwards guitar solos and adding more effects, but that in turn made many songs difficult to play live — part of the reason the Beatles decided to quit touring. Axis features a wide variety of tracks, from the melodic and more relaxing “Little Wing” and “Castles Made of Sand”, to the psychedelic “If 6 Was 9” and “Bold as Love”, and the upbeat “Ain’t No Telling” and “Little Miss Lover.” Natural imagery fills this album, with lines like “golden rose, the color of the dream I had/ Not too long ago… There you were under the tree of song, sleeping so peacefully.”