Owl City's "Fireflies" (Universal Island) started a second week as the U.K.'s favorite single, as Paolo Nutini's "Sunny Side Up" (Atlantic/Warner Music) returned to No. 1 on the artist album chart.

But perhaps the biggest news came on the separate compilations chart, where " Hope For Haiti Now" (MTV Networks), the all-star soundtrack from MTV's recent telethon for victims of the Haiti earthquake, debuted at the top. It is the first digital-only album to top the U.K. compilations chart.

The 20-track benefit album, digitally released Jan. 22, thus repeats its instant U.S. chart-topping success. Retailing for £5.99 ($9.55) in the U.K., it features contributions from Stevie Wonder, Sting, Coldplay and Alicia Keys among many others. It moved more than 22,000 copies in the U.K., according to the Official Charts Company.

Nutini's sophomore album was back at the top of the Jan. 31 artist chart as Alicia Keys' "The Element of Freedom" (J/Sony Music Entertainment) climbed 6-2 to reach a new peak. Its single "Empire State of Mind Part II" also improved 15-7. Florence and the Machine's "Lungs" (Universal Island), No. 1 for the last two weeks, fell to No. 3, while Dutch classical composer-conductor-violinist Andre Rieu improved again 6-4 with "Forever Vienna" (Decca/Universal).

Alvin & the Chipmunks' "Alvin & the Chipmunks 2 - The Squeakquel" (Rhino/Warner Music) raced 22-6, easily the biggest-ever U.K. success to carry the name of the long-running U.S. novelty act. British acoustic-based band Mumford & Sons' "Sigh No More" (Universal Island) climbed back to its highest position with a 10-7 move.

"Fireflies" bagged a second week atop the singles chart as the "Glee" Cast's cover of Journey's "Don't Stop Believin'" (Epic/Sony Music Entertainment), climbed again 3-2. Also on Epic, JLS climbed 10-6 with "One Shot" while "Young Forever" (Roc Nation/Warner Music) by Jay-Z featuring Mr. Hudson, jumped 13-10. The highest new entry on the chart, at No. 17, was "If We Ever Meet Again" (Interscope/Universal) by Timbaland featuring Katy Perry.

Lady Gaga does the double on Billboard's composite pan-European charts, extending her reign on European Albums with "The Fame" to a fourth consecutive week and climbing back 2-1 on Hot 100 Singles with "Bad Romance" (Interscope/Universal).