Sergei Rachmaninoff - 14 Romances, Op. 34

Vocalise, Op. 34, No. 14, is a song by Sergei Rachmaninoff, composed and published in 1915 as the last of his "Fourteen Songs", Op. 34. Written for high voice (soprano or tenor) with piano accompaniment, it contains no words, but is sung using any one vowel (of the singer's choosing). It was dedicated to soprano Antonina Nezhdanova. Although the original publication stipulates that the song may be sung by either soprano or tenor voice, it is usually performed by a soprano. It is sometimes transposed into a variety of keys, allowing performers to choose a vocal range more suitable to their natural voice, so that artists who may not have the higher range of a soprano can perform the song.

From A Masters Recital - Live - Tucson, AZ