He also toured with Bessie Smith, a top attraction of the Theater Owners Bookers Association. Okeh used the images of Louis Armstrong and Johnson in ads for the Defender. In December 1927, Johnson recorded in Chicago as a guest artist with Louis Armstrong and His Hot Five, paired with the banjoist Johnny St. Cyr. He played on the sides "I'm Not Rough", "Savoy Blues", and "Hotter Than That". The most famous of the three sides, "Hotter than That," encompassed the New Orleans traditions of polymetric tension, scar, dialogue, collective improvisation, and timbral diversity. In an unusual move, Johnson was invited to sit in with many OKeh jazz groups. In 1928, he recorded "Hot and Bothered", "Move Over", and "The Mooche" with Duke Ellington for Okeh. He also recorded with a group called the Chocolate Dandies (in this case, McKinney's Cotton Pickers). He pioneered the guitar solo on the 1927 track "6/88 Glide", and on many of his early recordings he played 12-string guitar solos in a style that influenced such future jazz guitarists as George Barnes, Charlie Christian and Django Reinhardt giving the instrument new meaning as a jazz voice. He excelled in purely instrumental pieces, some of which he recorded with the white jazz guitarist Eddie Lang, with whom he teamed in 1929. Much of Johnson's music featured experimental improvisations that would now be categorized as jazz rather than blues. According to the blues historian Gérard Herzhaft, Johnson was "undeniably the creator of the guitar solo played note by note with a pick, which has become the standard in jazz, blues, country, and rock". Johnson's style reached both the Delta bluesmen and urban players who would adapt and develop his one-string solos into the modern electric blues style. However, the writer Elijah Wald declared that in the 1920s and 1930s Johnson was best known as a sophisticated and urbane singer rather than an instrumentalist: "Of the forty ads for his records that appeared in the Chicago Defender between 1926 and 1931, not one even mentioned that he played guitar." Johnson's compositions often depicted the social conditions confronting urban African Americans ("Racketeers' Blues", "Hard Times Ain't Gone Nowhere", "Fine Booze and Heavy Dues"). In his lyrics he captured the nuances of male-female love relationships in a way that went beyond Tin Pan Alley sentimentalism. His songs displayed an ability to understand the heartaches of others, which Johnson saw as the