Bert Weedon, a British guitarist whose popular instructional manual “Play in a Day” taught the instrument to a generation of young hopefuls — young hopefuls named Pete Townshend, Eric Clapton, John Lennon and Paul McCartney — died on Friday at his home in Beaconsfield, in the English county of Buckinghamshire. He was 91.


A friend, John Adrian, confirmed the death to the news service Agence France-Presse.


Mr. Weedon was famous in Britain as a soloist, studio musician and television personality. He was originally trained as a classical guitarist, and over time he accompanied a spate of marquee names, including the operatic tenor Beniamino Gigli and visiting American artists like Frank Sinatra, Nat King Cole and Judy Garland.


One of Britain’s earliest ambassadors for the electric guitar, Mr. Weedon was known for his unflashy — and decidedly un-rock ’n’ roll — stage presence. In its obituary on Friday, the British newspaper The Telegraph wrote:


“As a television performer in the late 1950s, when he was in his 30s, Weedon cut a curious figure, looking more like a bank manager than a guitar hero. He had crinkly hair, beady eyes, a blob of a nose and a roguish smile, and invariably appeared in a dark suit and white shirt.”


“Play in a Day” was first published in 1957, and the advice it contained was equally sober. Besides teaching readers how to hold the instrument and introducing basic chords, Mr. Weedon urged moderation in matters of volume.


“As I travel up and down the country, I meet many groups who try to blast their way to success with too much noise and not enough talent,” he lamented in 1997 in an interview with The Independent.


“Play in a Day,” which has been translated into several languages and remains in print, has sold more than two million copies worldwide, according to Mr. Weedon’s Web site.


Mr. Weedon often expressed delight that so many guitarists, famous and un-, had learned to play from his book. (The roster of the famous also includes George Harrison, Keith Richards and Sting.) But he deplored the lack of tender physical consideration some of them showed the instrument.


“I can’t understand why anyone should want to smash a cup and saucer, let alone a guitar,” he told The Independent in the same interview. Though it did not specifically cross his lips, Mr. Townshend’s name doubtless coalesced in many readers’ minds.


Herbert Maurice Weedon was born in East London on May 10, 1920. His father, a driver on the London Underground, was part of an amateur song-and-dance act, and young Bert often accompanied him to the railwaymen’s clubs at which he performed.


At 12 Bert bought his first guitar, a battered flea-market specimen, for 75 pence. (In 2003, Mr. Weedon won libel damages — undisclosed but reported to be substantial — from the BBC, which had erroneously stated in a news release for one of its radio shows that he had learned to play in prison.)


By the time he was 14, Bert had left school to work as an office boy, taking guitar lessons from a local classical teacher. During World War II he was a rescue worker amid the London blitz; after the war he was a mainstay of the BBC’s house band.


Mr. Weedon’s first marriage ended in divorce. Survivors include his second wife, Maggie; two sons, Geoffrey and Lionel; and grandchildren.


In 2001, Queen Elizabeth II presented Mr. Weedon with the Order of the British Empire. At the ceremony, Her Majesty asked him whether he had brought his guitar along. His reply, and her musical requests, if any, are unrecorded.