The works by Mason Bates that tend to draw the most attention are his orchestral scores and the 2017 opera The (R)evolution of Steve Jobs. But the American composer has also penned a sizeable number of pieces for chamber ensembles and voices. Bates’s versatility is further revealed on this disc of superb choral works featuring the inspired Cappella SF.

In Sirens, six movements of beguiling and varied settings for a cappella chorus, Bates embraces an assortment of languages and musical styles to depict the seductive creatures of mythology and, with a passage from the New Testament, Jesus’s holy powers of persuasion. The composer’s keen imagination for colour and motion can be felt in undulating waves evoked by the choristers in an excerpt from The Odyssey. When Heine is the poet, the music reflects the German source, while a text by Pietro Aretino receives Italianate treatment and a movement in native Quechua reflects that culture.

Bates is noted for his novel employment of electronics, which are put to striking use in Mass Transmission, scored also for chorus, soloists and organ. The three movements portray the real-life tale of long-distance radio transmissions between a mother (in Holland) and daughter (in Java). Amid occasional radio static, the piece weaves a poignant narrative in which choral lines – based on historical texts – are mixed with sampled sounds and vibrant organ sonorities.

Both works could hardly have more incisive and seamless champions than Cappella SF, which Ragnar Bohlin, chorus director of the San Francisco Symphony Chorus, founded in 2013. (He is paid tribute here at the end in Bates’s riotous Rag of Ragnar.) Lucky is the composer whose music is brought to life by these exceptional singers.