Les Paul, the Grammy Award-winning guitar virtuoso and inventor who helped bring his instrument to the forefront of jazz performance, died of pneumonia Thursday at a hospital in White Plains, N.Y. He was 94. Paul first came to prominence for his fast and flashy jazz-guitar style. In the 1940s and early 1950s, he and singer Mary Ford, his wife, had hits with 'How High the Moon,' 'The Tennessee Waltz,' 'Vaya con Dios' and 'The World is Waiting for the Sunrise.' All along, he refined musical inventions in his workshop. He was an early designer of an electric guitar that had a solid body, and his model managed to reduce sound distortions common to acoustic instruments. He actively promoting such guitars for the Gibson company, and the Les Paul line of guitars became commonplace among such musicians as bluesman Eric Clapton, jazzman Wes Montgomery and rocker Pete Townshend. Paul called his first solid-body guitar 'the Log.' It was made of a four-inch thick piece of wood from a nearby railroad track, a neck he borrowed from an Epiphone guitar and two pickups to give it the electric pulse. Audiences and music executives laughed at the ungainly device, and he spent years honing its visual appeal. He said his efforts were toward one goal: to change the way people saw the guitar. 'I wanted people to hear me,' he told the publication Guitar Player in 2002. 'That's where the whole idea of a solid-body guitar came from. In the '30s, the archtop electric was such an apologetic instrument. On the bandstand, it was so difficult battling with a drummer, the horns, and all the instruments that had so much power. 'With a solid-body, guitarists could get louder and express themselves,' he said. 'Instead of being wimps, we'd become one of the most powerful people in the band. We could turn that mother up and do what we couldn't do before.' He played a key role in developing the eight-track tape recorder, and used the device to play many parts on the same recording, a process now called multitracking. Such early work in overlaying sound contributed to the richness and distinctiveness of his recordings. Paul earned the nickname 'the wizard of Waukesha,' after the town in Wisconsin where he was born Lester William Polfuss on June 9, 1915. His father was an auto-garage mechanic. As a boy, Paul taught himself music on his mother's player piano, mimicking the notes with his own hands. An admirer of the blues and country troubadours he heard on the radio, he imitated their songs with his own harmonica and mail-order guitar. He played both instruments simultaneously by making his own harmonica holder. As a teenager, he played dates at a drive-in restaurant, where he experimenting with amplified sound to reach the open-air audience. He stuck a phonograph needle inside his acoustic guitar and wired it to a radio speaker. Adopting the moniker 'Rhubarb Red,' he left high school and joined a traveling cowboy band and later played on the 'Barn Dance' program on WLS radio in Chicago. He named one of his early groups the Original Ozark Apple Knockers. Not wishing for a career in hillbilly music, he convinced two friends -- guitarist Jimmy Atkins (Chet's brother) and bassist Ernie Newton -- that he knew Paul Whiteman, the prominent big-band leader. The trio went to New York in 1937, only to be kicked out of Whiteman's office. They were waiting for the elevator back down when they saw bandleader Fred Waring next to them. He already had dozens of musicians, but Paul insisted he hear the trio's lightning-fast tempo -- timed to please Waring before the elevator arrived. He was hooked, and they got a job on his NBC show. Around this time, Paul also became a consultant to the Gibson company, testing its new models. Not until a decade later, in 1952, and after a rival company developed a similar model, did Gibson see the selling potential of Paul's solid-body electric guitar. They sought his endorsement on their own design. Meanwhile, he had disagreements with Waring about the continued use of the electric guitar. He announced he wanted to be the accompanist for Bing Crosby, one of the most popular singers in the country. It took Paul two years to meet Crosby and worked as musical director for two Chicago radio stations before impressing the crooner during a musical date at a Los Angeles club. Crosby arranged for a recording session at Decca records, where they made 'It's Been a Long, Long Time,' 'Tiger Rag' and other titles that were best-sellers. In the early 1940s, Paul worked for Armed Forced Radio Service and became a staff musician at NBC, accompanying the Andrews Sisters and other pop singers. He jammed the blues with pianist Nat 'King' Cole in Norman Granz's first Jazz at the Philharmonic concert series in 1944. Their quicksilver note-for-note matching of solos created howls of approval from the audience. He also had musical dates worldwide, once meeting his idol, Gypsy guitarist Django Reinhardt. On Crosby's advice, Paul created his own recording studio, both to help his guitar career and his interest in electronics. He began to take advantage of new, still bulky, tape-recording machine technology. Facing initial skepticism, he persuaded Ampex to market his eight-track tape recorder. After hundreds of false starts, he began recording with these new devices in the late 1940s and can be heard on such standard and novelty numbers as 'Nola,' 'Josephine,' 'Whispering' and 'Meet Mister Callahan.' His version of 'Lover' boasted him playing eight electric guitar parts, which he electronically wove into a single record. It was a sensation. Married at the time, he also had been seeing Ford, whom he had hired as a singer and guitarist. Both were in the auto wreck, on an icy patch of road in Chandler, Okla., that almost killed Paul in 1948. Paul's right arm was crushed, and one doctor suggested amputation. Instead, he had it fixed at a right angle so he could play his instrument. The next year, Paul divorced his first wife, Virginia Webb Paul, and married Ford. The new couple settled in Mahwah, N.J., and continued to work together on a series of albums for Capitol and Columbia in the 1950s, including 'The New Sound' and 'Time to Dream.' The rigorous touring schedule and Ford's alcohol addiction damaged their marriage. Meanwhile the public demand for rock `n' roll harmed their careers. They divorced in 1964. Survivors include a companion, Arlene Palmer; two sons from his first marriage; and a son and daughter from his second marriage; five grandchildren; and five great-grandchildren. A daughter from his second marriage died in infancy in 1954. (Optional Add End) Paul, who had long ago made his fortune, tried to settle into retirement in the 1960s as the popularity of rock-and-roll music grew. He made occasional recordings, notably the album 'Chester and Lester,' for which he shared a 1976 Grammy for best country instrumental performance with Chet Atkins. Paul was inducted into the Rock and Roll Hall of Fame in 1988 and won two more Grammys, in 2006, for his album 'Les Paul & Friends: American Made, World Played.' He gradually re-entered public performance, obtaining a regular date at Fat Tuesday's in New York through the 1990s. For fans and fellow musicians, including Billy Joel, catching Mr. Ford at Fat Tuesday's was a Monday-night must. He was a sprightly presence at the club, even after he developed arthritis that left him with use of only two fingers in his left hand. 'If you're stubborn, it can be done,' he once told The Washington Post. 'I've been playing with what fingers I have left. If they'll put up with it, I can put up with it.' 