Robert Carl's "Symphony No. 7 (Infinity Avenue)" is listed as a symphony for laptop and chamber orchestra. As near as I can tell, that 2020 work grew out of a 2015 improvisation that also goes by "Infinity Avenue." And I think that's about all you need to understand the jumping off point for Carl's work.

Robert Carl Infinity Avenue (Neuma Records)

When I was researching this I came across the sheet music for the symphony. If that gives you a bit of a rise, you should check it out for yourself. It's pretty wild. And while the charts for the first work, "Updraft" might seem tame, it is a work for 10 trombones. It's haunting as hell, with trombones reaching unexpected heights (literally).

Carl likes to shift his palette, and he uses just about every instrument in the book on this two-disc set. What all of them do is show off his focus on harmonics. Specifically, overtones. Each piece begins with a starting position and then builds through harmonics. And when you enlist 10 trombones (or five double basses, as on "Night Garden"), the effect is striking.

Perhaps I've lost you. Carl is one of the more rigorously conceptual composers around, and this selection of his works from the last 20 years more than proves that point. Just as the harmonics build notes upon notes, these works construct a myriad of ideas from a single point. Spellbinding.