The concerto is through-composed in a single movement lasting approximately 25 minutes.[1] MacMillan wrote the concerto while in lockdown from the COVID-19 pandemic, about which he remarked, "It seemed like a time when things tended to be more introverted. I suppose I turned inwards as well. Maybe that had an effect on the music."[3] The music was composed around three chords, from which MacMillan built a three-note theme that develops throughout the concerto.[1]
The concerto has been generally praised by music critics. Reviewing the world premiere, Simon Thompson of The Sunday Times called the concerto "a radiant jewel of a piece that seemed to inhabit a multitude of human emotions while guiding the listener through them with luminous clarity." He added, "MacMillan builds his concerto from the three chords of its opening, chords that open up a universe of mysteriously infinite possibilities, and which launch 25 minutes of music that is by turns serene, adventurous and threatening."[4] Richard Sylvester Oliver of the Texas Classical Review similarly remarked, "MacMillan's eclectic musical language, marked by a firm emotional directness, is an elegant marriage of the modern and traditional, often spinning simple ideas into complex textures without sacrificing accessibility."[5]
Rowena Smith of The Guardian was slightly more critical, however, describing it as "an at times intensely discomfiting piece, the single-movement 25-minute span a journey through a dark landscape with the soloist cast in the role of traveller across an ever-shifting orchestral terrain." She concluded, "It is a work as intriguing and evocative as it is approachable, even if at first hearing the shift into the light in the closing bars doesn’t quite convince."[6]
