supplanted by the guitar in the early years of rock and roll). A number of mainland-based stringed-instrument manufacturers, among them Regal, Harmony, and especially Martin, added ukulele, banjolele, and tiple lines to their production to take advantage of the demand. The ukulele also made inroads into early country music or old-time music parallel to the then-popular mandolin. It was played by Jimmie Rodgers and Ernest V. Stoneman, as well as by early string bands, including Cowan Powers and his Family Band, Da Costa Woltz's Southern Broadcasters, Walter Smith and Friends, The Blankenship Family, The Hillbillies, and The Hilltop Singers. Post-World War II From the late 1940s to the late 1960s, plastics manufacturer Mario Maccaferri turned out about 9 million inexpensive ukuleles. The ukulele remained popular, appearing on many jazz songs throughout the 1950s, '60s, and '70s. Much of the instrument's popularity (particularly the baritone size) was cultivated by Arthur Godfrey on The Arthur Godfrey Show on television. Singer-musician Tiny Tim became closely associated with the instrument after playing it on his 1968 hit "Tiptoe Through the Tulips". Post-1990 revival After the 1960s, the ukulele declined in popularity until the late 1990s, when interest in the instrument reawakened. During the 1990s, new manufacturers began producing ukuleles and a new generation of musicians took up the instrument. Jim Beloff set out to promote the instrument in the early 1990s and created over two dozen ukulele music books featuring modern music and classic ukulele pieces. All-time best-selling Hawaiian musician Israel Kamakawiwo'ole helped repopularize the instrument, in particular with his 1993 reggae-rhythmed medley of "Over the Rainbow" and "What a Wonderful World," used in films, television programs, and commercials. The song reached number 12 on Billboard'''s Hot Digital Tracks chart the week of January 31, 2004. The creation of YouTube helped revive the popularity of the ukulele. One of the first videos to go viral was Jake Shimabukuro's ukulele rendition of George Harrison's "While My Guitar Gently Weeps" on YouTube. The video quickly went viral, and as of September 2020, had received over 17 million views. Construction The ukulele is generally made of wood, though variants have been composed partially or entirely of plastic or other materials. Cheaper ukuleles are generally made from plywood or laminated woods, in some cases with a soundboard of a tonewood such as spruce. More expensive ukuleles are made of solid hardwoods such as mahogany. The traditionally preferred wood