Jesse McCartney slides comfortably into the top slot on the US pop radio chart this week with the smooth soul-pop of "Leavin." It is his first visit to the top of pop radio airplay as an artist. Check out much more action in this week's coverage of the US pop music charts.

_{Photo courtesy Hollywood Records}

Three years ago the Denver-based alternative hip hop collective Flobots released the album Flobots Present...Platypus. It included a song called "Handlebars." The album ultimately sold approximately 3000 copies. It wasn't a bad number for a local band that counted an opening slot for fellow local band The Fray as among their biggest shows. However, few in the music industry would have predicted the band were destined to be one of the hottest pop music sensations in just 3 years.

In October 2007 Flobots released the album Fight With Tools. By early in 2008, the band had drawn the attention of major label Universal Republic who made the decision to re-release Fight With Tools and include the earlier single "Handlebars." The politically charged content of "Handlebars" first gained attention from modern rock radio. The song quickly landed in the top 3 on Billboard's Modern Rock chart in May 2008. Fight With Tools was re-released on May 20, 2008 and leaped to #15 on the chart in June.

Driven by strong digital download success and a video that has drawn over 4,000,000 views on YouTube, "Handlebars" is now heading its way up the mainstream pop singles chart. It is arguably the first work since Green Day's landmark American Idiot to ride political commentary to mainstream pop success. This week "Handlebars" sits inside the top 20 in digital downloads of songs and has just arrived inside the top 40 on the pop singles chart. Flobots are making pop fans think once again.

Watch "Handlebars"

_{Photo courtesy Universal Republic}