Passage: Hitmixes is the second extended play (EP) by American singer Lady Gaga, released on August 25, 2009. Featuring remixes of songs from Gaga's debut album, The Fame (2008), the album was only released in Canada, by Universal Music Canada. Hitmixes features mixes from various musicians, including RedOne and Space Cowboy, who previously worked with Gaga. The EP hosts 1980s-influenced and house remixes. Hitmixes received positive reviews from the Calgary Herald and Blare Magazine, and peaked at number eight on the Canadian Albums Chart.

Question: who is the singer in Hitmixes?
Lady Gaga