Paolo Gregoletto joined Trivium on September 5, 2004 when Matt Heafy and Travis Smith were in the studio demoing new material for what would become Ascendancy. Gregoletto was in the studio with Jason Suecof next to where Trivium were demoing, and was told by Suecof that they needed a bass player. After jamming with Heafy and Smith, Gregoletto agreed to record for Ascendancy and tour to promote it with the band. Gregoletto originally had no intentions of staying with Trivium, but wanted touring experience. He joined just in time for the tour Trivium booked with Machine Head. He replaced Brent Young just after the band had finished recording Ember to Inferno.
Gregoletto is known to be most frequently interactive with Trivium fans, often answering questions, posting many videos, photos, and band updates via his official Facebook, YouTube and Twitter. Paolo has also recently opened an online forum accessible at www.paolo-gregoletto.com. Since 2013 he has written a monthly column for the UK's Bass Guitar Magazine.
In an interview with Bass Guitar magazine (July/August), Gregoletto revealed that he uses a variety of techniques to perform his basslines, as is typical of modern bassists. While he primarily used a pick to perform during the tour for Ascendancy, he now more frequently adopts a two fingered plucking style to pick out the more elegant counter-melodies and rapid pentatonic accompaniments necessary for some of Trivium's material. He will also frequently use a three-fingered plucking style, as favored by Billy Sheehan, in order to achieve a gallop rhythm (one eighth note followed by two sixteenth notes) in the style of Iron Maiden's Steve Harris. In the same article, he revealed that he prefers to warm up by performing chromatic exercises up and down the whole neck of the bass, using both plucking and picking styles.