[1] Beginning her career in 2009 as a performer at various festivals and music contests in Quebec, she released her self-titled debut EP in 2012.

[4] She was a shortlisted nominee for the SOCAN Songwriting Prize in 2014 for her song "La fièvre des fleurs",[5] and L'Alchimie des monstres was a nominee for Francophone Album of the Year at the Juno Awards of 2015.

At the Gala de l'ADISQ in 2018, she won the Prix Félix for Female Singer of the Year.

[8] Her 2020 album Notre-Dame-des-Sept-Douleurs was shortlisted for the 2021 Polaris Music Prize.

[9] Her brother, Mathieu David Gagnon, is a composer and arranger most noted for the instrumental music project Flore Laurentienne, although he has also composed orchestral arrangements for Pelgag's albums.