The trombonist continued to perform and record with Schaphorst's ensemble and the Either/Orchestra -- appearing on a number of Accurate label albums by both groups -- until, like many creative jazzers on the Boston scene, he was drawn to New York and the city's fertile avant jazz environment. A Knitting Factory regular, Hasselbring participated in bands led by the likes of Bobby Previte, Frank London, Jerry Granelli, Satoko Fujii, and Matt Darriau (Ballin' the Jack) beginning in the mid- to late '90s and continuing into the 2000s. His trombone also slid through the arrangements of the Balkan street band stylings of Slavic Soul Party!, a group whose early membership included reedman Chris Speed, like Hasselbring a New England Conservatory graduate who had become a key member of the Brooklyn-based avant jazz community.
Meanwhile, over a dozen musicians had passed through the ranks of Hasselbring's Mellow Edwards group, and in the early 2000s the trombonist felt a name change was in order, christening the band the New Mellow Edwards and ultimately solidifying the lineup into an impressive quartet including bassist Trevor Dunn, drummer John Hollenbeck, and Speed on tenor sax and clarinet. In 2006, Speed founded the independent Skirl Records label, and the New Mellow Edwards' eponymous debut CD arrived on Skirl that same year. Three years later, Skirl issued the group's sophomore album, Big Choantza.
In 2010 Hasselbring received support from Chamber Music America's New Jazz Works Commissioning and Ensemble Development program for his most ambitious project yet, Number Stations, a composed and improvised set based on the curious phenomenon of actual shortwave radio stations that broadcast sequences of numbers thought to be coded messages sent by intelligence agencies to their spies in various countries around the world. Hasselbring conceived the piece for an extended ensemble consisting of the New Mellow Edwards (now with Ches Smith rather than John Hollenbeck on drums) combined with Decoupage, another band that he leads. In addition to Hasselbring on trombone, Decoupage features guitarist Mary Halvorson, Slavic Soul Party!'s Matt Moran on vibes and marimba, and percussionist Satoshi Takeishi; with participation from both the New Mellow Edwards and Decoupage, Number Stations was thus performed by a seven-piece aggregation drawing from two distinct sides of Hasselbring's previous creative output. The Cuneiform label (also home, by the way, to the Claudia Quintet, featuring Hasselbring collaborators Speed, Hollenbeck, and Moran) released Number Stations on disc in January 2013. ~ Dave Lynch, Rovi