[9] In her youth, Leon and some of her friends were part of a blues band[7] called "Walking Spanish" which performed at various music festivals in Sweden.

[1] Leon's musical idols and inspirations include Beyoncé, Mariah Carey, Eminem,[7] Whitney Houston and Michael Jackson.

[10] Leon's professional music career began in 2003 when she at the age of 13 joined the Swedish pop group Play as lead singer in December 2003.

[7] Bagge called back almost immediately after receiving the demo and travelled to Gothenburg the next day to hear Leon perform in person and ask her about her life goals.

[7] Play performed together with various artists during the tour, including Aaron Carter and Destiny's Child;[6] Leon also had a dinner with her idol Beyoncé.

[11] In 2005 the group then released a compilation of hits, Girl's Mind, though only songs from Hamlin's time as lead singer were featured.

Made in Sweden saw the producers attempt to forge successful musical artists; in Leon's case the programme followed her over the course of two months as she worked on and prepared her first solo studio album.

The song was co-written by Leon, along with songwriters Jörgen Elofsson, Lisa Desmond and Jesper Jakobson[24] and debuted at number 10 on the Swedish music chart Svensktoppen.

[28] The song was written by songwriters Karl-Ola Kjellholm, Jimmy Jansson, and Louise Winter and was performed by Leon in Örnsköldsvik on 22 February 2014.

[35] On 7 April 2021, Leon partook in the Clubhouse talk "Women in Music – Goddess Power Unite", hosted by Swedish musician Josefine.

The talk also featured various other female musicians and music creatives and also brought attention to the UK-based social organization Girls Out Loud.

[32][33] In October and November 2022, Leon joined fellow Swedish-Iranian singer Arash on a tour of North America, performing concerts in support of the Mahsa Amini protests in Iran.

[36] On 14 April 2023, she stated that she would no longer be using the stage name "Janet Leon", citing as reasons the strange experience of growing up in the music industry and not being herself.