In 1991, Scabbia began singing professionally as a touring musician for other bands and providing backing vocals. Later that year, she met male vocalist Andrea Ferro and bass player Marco Coti Zelati (who would be the future two of Lacuna Coil's founding members) in Milan's Midnight Club.

At the time their band was named Ethereal, and Scabbia was initially employed only as a session singer. She was asked to record backup vocals for the choruses of their demo tape, but the band members liked the way the male and female vocals sounded together, and they asked her to be a permanent member. After several changes in the band's line-up, the members were reduced to Ferro, Coti Zelati and Scabbia.