Tambour is Castonguay's primary musical project. His work is the result of extensive research in minimalist and neo-classical movements. His meticulous compositions build a dreamy yet uplifting narrative atmosphere. He has previously released a full length LP under the name projet.hertz (2013) and two EPs as Tambour entitled Chapitre I (2015) and Chapitre II (2016) with the label Moderna Records.
In 2018, Simon presented a new single "Silhouettes". The release is accompanied by a video / short film co-produced with Telescope Films. His next EP Constellations (ou comment arrêter le temps) is to be released August 23rd 2019.