Definition of "alti"

The four parts of Trionfo del Tempo are for two sopranos and two alti.

1857, James Lowe, transl., The Life of Handel, London: Trübner and Co., […], translation of original by Victor Schœlcher, page 147

Another of his works which would be very attractive is the Psalm 23d for two soprani and two alti.

1858 April 24, “My Diary. No. 3”, in John S. Dwight, editor, Dwight’s Journal of Music, a Paper of Art and Literature, volume XIII, number 4 (Whole No. 316), Boston: Oliver Ditson and Co., […], published 1859, page 28, column 1

The new chorus of angels, “Fear thou not,” for two soprani and two alti, is a smooth piece of devotional writing, excellently adapted to its position in the work, Peter’s air, “The heavens are opened,” with its appropriate harp accompaniment, immediately following it with increased effect.

1871 January 1, “Mr. Benedict’s “St. Peter” at St. James’s Hall”, in The Musical Times, and Singing Class Circular, volume XIV, London Sacred Music Warehouse: Novello, Ewer and Co., […], page 746, column 1

Points of special effect were the music—for two first trebles and two alti—in which Mendelssohn has wrapped the words of the heavenly voice, “Saul! Saul! why persecutest thou Me?” the drums at the opening of “Arise and shine,” the brass interludes (as well as the general grandeur) of “Sleepers wake”—surely the finest treatment of a choral known to music—the well-known violoncello accompaniment to “Be thou faithful” (rendered by Mr. Pettitt); and the always fresh grace of “How lovely are the messengers.”

1874 January 31, “Orchestral Service at St. Paul’s”, in The Musical Standard, volume VI, London: Reeves & Turner: […], page 67, column 1

[…] Introduzione al salmo Miserere, for two soprani, two alti, and orchestra; […]

1890, “PORPORA, NICCOLO (Niccola) ANTONIO”, in John Denison Champlin, Jr., William Foster Apthorp, editors, Cyclopedia of Music and Musicians, volumes III: “Naaman–Zwillingsbrüder”, New York: Charles Scribner’s Sons, page 144, column 1

M. Kashkin, who was staying with Tchaikovsky while he was engaged upon this, says that at first the composer found it extremely difficult, but after a few days he declared he had quite solved the mysterious art of writing for this special combination of instruments—two violins, two alti, and two violoncellos.

1900, Rosa Newmarch, Tchaikovsky: His Life and Works, with Extracts from His Writings, and the Diary of His Tour Abroad in 1888, London: Grant Richards, pages 101–102

My Lady Chlo’ a negro song harmonized for two soprani and two alti by H. Clough-Leighter.

1903, Dominicana: A Magazine of Catholic Literature, volume IV, page 377

This introduction, which, like the rest of the opera, is charmingly scored, is extended to over 60 bars; the chorus (two soprani and two alti,) then enter with the theme I have quoted.

1904 November 1, The Monthly Musical Record, volume XXXIV, London: Augener & Co., page 202, column 1