Winner of more than about thirty competitions, at the age of nineteen, Hildegarde Fesneau carries off the Fifth Prize at Long-Thibaud-Crespin competition in the Champs-Elysées Theatre and becomes then Révélation Classique ADAMI 2015. Since then, she enters Augustin Dumay's class at Queen Elisabeth Music Chapel.

After Long-Thibaud-Crespin competition, her career takes fllight and she gets invited many times to play in Salle Pleyel and Salle Gaveau  in addition to many festivals like Colmar, Sully sur Loire, Pablo Casals in Prades as well as in Guadeloupe and in Greece.

In February 2015, she gets to play at the Royal Albert Hall in London and is revealed the month after "Young Talent" in the french magazine Diapason (no 633). Yves Henry and Déborah Nemtanu showed interest for her personnality an she often has the occasion to perform with them, as well as she continues to develop her duet with the pianist Antoine De Grolée, who also won the Fifth Prize of Long-Thibaud-Crespin competition in 2007. Younger, she played in a duet with her pianist sister Zéphyrine, who with she had the privilege to be invited in Lorin Maazel's concerts planning as well as in the first part of a Seiji Ozawa concert whose they could appeal to his precious musical advice. At the age of fifteen, Hildegarde Fesneau was selected to play several contemporary works as a soloist in Salle Pleyel, with the London Symphony Orchestra conducted by François-Xavier Roth and a hundred young musicians within the framework of "Take a bow" Project. In January 2016, she is invited to play at the Zénith in Pau (France) "Carmen's Fantasy" by Sarasate conducted by Fayçal Karoui for the three New Year's galas and is once again invited in April 2017 to play Barber's violin concerto. The month after, she performs in Théâtre des Bouffes du Nord within the framework of Adami and is the subject of several interviews and articles on the Radio (France Musique, Radio Classique, RTL) and in the Nouvelle République.

She is benifiting from Fondation SAFRAN and Fondation Banque Populaire, she plays on a magnificent violin made by Tommaso Balestrieri in 1756 and lent by Zilber-Vatelot-Rampal Association.