The power of popular music and recordings is overwhelmingly evident in the live entertainment business. Popular artists performing the songs they have recorded create the vast majority of the income generated in the live performance stream. Pollstar estimated that ticket sale revenues for major concerts in North America amounted to $4.2 billion in 2008 and their top 100 tours only included five non-musical acts (comediennes Jeff Dunham, Chris Rock, George Lopez, and Ron White, and magic act David Copperfield), which accounted for less than 2 percent of ticket sale revenues. As with recording sales, the majority of the revenues are generated by a small number of the artists. The top 20 tours accounted for nearly 25 percent of ticket sale revenues.