Culture express has been taking a look back at 2011's biggest musical acts. On Wednesday, we presented you Coldplay and Justin Bieber. And today, we will have a quick look back at what pop divas Lady Gaga and Beyonce achieved in 2011.

Lady Gaga was a regular presence at award shows throughout the year.

2011 was a big year for pop star Lady Gaga. When her album "Born This Way" was released in May, 1.1 million copies sold in the first week. It outsold the next 42 albums on the Billboard chart combined. As of October, worldwide sales had surpassed 8 million copies. And she continues to release ambitious videos - most recently the 13-minute epic "Marry the Night," which grabbed 5 million views in less than 48 hours.

Lady Gaga was a regular presence at award shows throughout the year. She won three Grammys in February, including best female pop vocal performance. She won two MTV Video Music Awards in August. And she was recently nominated for three Grammys for next year, including best album.

2011 was also a good year for Beyonce.

2011 was also a good year for Beyonce. The singer released a new album, announced she was pregnant and introduced a fragrance, "Pulse." The pop diva's fourth solo studio album, "4" was released in June and debuted at number one on the Billboard 200, with first-week sales of 310,000 copies. As of December 2011, the album had sold 956,000 copies in the U.S. The year also saw Beyonce headline the iconic Glastonbury Music Festival in the U.K.

In November the star received two nominations for the 54th Grammy Awards; Best vocal Collaboration for "Party," and Best Long-Form Music Video for I Am World Tour.