It also had something in common with John Cage's "Solos" (1958), a set of five unaccompanied instrumental pieces, and his "Fontana Mix" (1958), an electronic work assembled from snippets of radio noise.
Mr. Glass went on to write "Songs and Poems" (2007), a set of seven movements for unaccompanied cello (outpacing Bach by one in his six suites) for Ms. Sutter.
Or so it seemed at first, when confronted with "Récitations" by the Greek composer Georges Aperghis, a set of 14 vivid short pieces for unaccompanied vocalist.
Between the piano work and the songs, Rose Mary Harbison, the composer's wife, played "Four Songs of Solitude," a set of atmospheric pieces -- some songlike, some in a quasi-dialogue form -- for unaccompanied violin.
His works include a set of 16 Lutheran masses (consisting only of the Kyrie and the Gloria); a collection of madrigals for unaccompanied singers, Geistliche Madrigalien ("Sacred Madrigals"); a set of sacred symphonies for one or two voices with strings and continuo; and 3 books of secular songs, Weltliche Oden ("Worldly Odes").
Another piece by Mr. Knussen, a setting of Rilke lyrics for unaccompanied soprano, was sung by Ms. Saffer in a way that showed off its exultant melody, its rhythmic suppleness and tug.
Mr. Koester said: "Braxton's prior record, his first, had moved only 200 copies the first year, so I knew I was going to have trouble selling a double record set of totally unaccompanied saxophone.
The central unaccompanied group consisted of two items from the Eton Choirbook – William Cornysh's Ave Maria, Mater Dei and Walter Lambe's Stella Caeli – plus Imogen Holst's Hallo, my fancy, whither wilt thou go? – a setting of the 17th-century Scottish poet William Cleland.
He has commissions and has recently written a series of unaccompanied Christmas carols.
The Obama administration had largely abandoned family detention since 2009, but rapidly expanded it two years ago, as a rising influx of unaccompanied minors and families traveling together from Central America set off a national uproar over immigration.
