Los Angeles: Singer-songwriter Christina Perri says she had to work hard on her second album `Head or Heart`, which released Monday.
The 27-year-old `A Thousand Years` singer took a year and over two months to write her second album, reported Hollywood Reporter.
"It allowed me to take time and be a little picky, so that`s why one has time to finally stop and be like, it`s done - but it allowed me to really be part of every single part," she said.
The musician said that the mixing process was the most difficult part of working on the album, which has singles like `Human` and `Burning Gold`.
Perri has collaborated with singer Ed Sheeran whom she called "one of her favourite people on the planet" for the duet `Be My Forever`.
"As much as I love the heart-wrenching stuff, I knew I had a happy song in me," she said of the duet.