When the series shifted from the WB to UPN for its sixth season, fans were treated to one of its most innovative episodes: the musical Once More With Feeling. Most prominently for Trachtenberg, whose ballet talents were showcased that week, she opens the episode’s coda, “Where Do We Go From Here?,” singing the opening title line a cappella.

The NYPD confirmed to PEOPLE that Trachtenberg was found "unconscious and unresponsive" in her Manhattan apartment on Wednesday, Feb. 26 and pronounced dead at the scene