Los Angeles, Nov 28 (IANS): Singer Katy Perry is mourning the loss of a close friend who died last week after suffering from cancer for long.

The singer, 34, posted the heartfelt tribute to Angelica "Geli" Cob-Baehler on Instagram Tuesday and explained how bigtime music executive, 47, played an incredibly important role in her career, reports people.com.

"Six days ago, one of my biggest champions and realest friends, Angelica Cob-Baehler moved on from this place," Perry began.

"She was one of the strongest women I have ever known - fighting her cancer like friggin' Rocky, enduring chemo, immunotherapy, a tracheotomy, feeding tubes for months on end, and experimental cancer treatment trials.

"I watched her go through many stages for over a year, but a few things remained constant: her sarcastic/wicked sense of humour, her positive outlook, and the incredible love she had for her family," she added.

Perry and Cob-Baehler have known each other for over a decade. At the start of her career in 2004, Perry had landed with Sony's Columbia Records, according to a 2012 profile by The Hollywood Reporter.

However, after things fell through with them, she ended up signing with Capitol Records thanks to help of Cob-Baehler who "stole her files" and "brought them to life" at the label, Perry explained.

Cob-Baehler played a massive role in the production of Perry's 2008 album "One of the Boys," which featured her breakthrough hit "I Kissed a Girl," according to Variety. She also helped with the development of Perry's next album "Teenage Dream."