Sheets of sound was a term coined in 1958 by Down Beat

Down Beat

Down Beat is an American magazine devoted to "jazz, blues and beyond" to indicate its expansion beyond the jazz realm which it covered exclusively in previous years. The publication was established in 1934 in Chicago, Illinois...

magazine jazz

Jazz

Jazz is a musical style that originated at the beginning of the 20th century in African American communities in the Southern United States. It was born out of a mix of African and European music traditions. From its early development until the present, jazz has incorporated music from 19th and 20th...

 critic Ira Gitler

Ira Gitler

Ira Gitler is an American jazz historian and journalist. Perhaps best known for The Biographical Encyclopedia of Jazz written with Leonard Feather—the most recent edition appeared in 1999—he has written hundreds of liner notes for jazz recordings since the early 1950s and is the author of dozens...

 to describe the new, unique improvisational style of John Coltrane

John Coltrane

John William Coltrane was an American jazz saxophonist and composer. Working in the bebop and hard bop idioms early in his career, Coltrane helped pioneer the use of modes in jazz and later was at the forefront of free jazz...

. Gitler first used the term on the liner notes for Soultrane

Soultrane (album)

-Personnel:* John Coltrane - tenor saxophone* Red Garland - piano* Paul Chambers - bass* Art Taylor - drums...

(1958).
Coltrane employed extremely dense improvisational yet patterned lines consisting of high speed arpeggio

Arpeggio

An arpeggio is a musical technique where notes in a chord are played or sung in sequence, one after the other, rather than ringing out simultaneously...

s and scale patterns played in rapid succession: hundreds of notes running from the lowest to highest registers.