My computer sings for you! I have recorded the sound of synthesized voices from a computer music program. This is quite a bit of fun. Give it a listen. It sings better than many humans do. Whether or not you choose to listen, technical information, links, and lyrics can be found lower on this page.

To hear the music: If you have Flash and JavaScript enabled, you will see a button at right. Click it, then a Flash player will appear in this space and replace these words. When you pick a song from its playlist, the song lyrics are displayed and the music starts automatically (give it time to load).
This page does not operate on handheld devices.
About the technology: In each song, the voice has been synthesized by inexpensive music software running on my home computer. The instrumental accompaniments are also generated by computer, mostly modeled from real instruments. These songs are very good. Most of the songs have been compressed for low bandwidth transmission, so you won't hear a lot of high-frequency overtones.
Some voices are partially modeled from my own English-language male voice. Others are partially modeled from different singers. Mispronunciations are not the fault of the software, since the sounds are within my control.
The synth voices are always on pitch and on tempo, unless instructed otherwise. In fast-tempo songs, a live singer omits or changes phonemes so that sounds can fit. The synth voices do not know what to omit unless enunciation is changed manually.
Since the technology creates voices from a limited number of parameters, it is not possible to make a synth voice indistinguishable from its live model. But that is not the purpose of the software.
Virtual Singer is an add-on to either Melody Assistant or Harmony Assistant, products of Myriad Software (Windows or Mac). When Virtual Singer is used with an enhanced voice, it is called Real Singer. Myriad's own technical explanation of Virtual Singer is part of the product documentation. I am just an ordinary user.
At Choralia you can find choir singing aids, using Virtual Singer. Elsewhere, you can hear a variety of Christmas carols with sheet music and Virtual Singer renditions, in native format or audio. The carols seem to be using default settings for the voices, so they are a bit more mechanical than the adjusted parameters that I used for my own demos.
Other technologies: Probably the first synth singing voice is Vocal Writer for Mac. Perhaps the most advanced, expensive synth singers use Yamaha's Vocaloid. Third-party studios record singers, and sell a large phoneme database that is driven by the included Vocaloid. Results vary. User demos can be found here.
Try the Wikipedia article, or this small vowel synthesizer. But there is more to voice synthesis than formants, particularly for consonants and other transitionals.
Nessun Dorma
Opera Turandot by Giacomo Puccini (1858-1924).
Completed by Franco Alfano (1876-1954). Seq. David Morris, at Aria Database.
Nessun dorma! Nessun dorma!
Tu pure, o Principessa, nella tua fredda stanza
guardi le stelle che tremano d'amore e di speranza!
Ma il mio mistero è chiuso in me, il nome mio nessun saprà!
No, no, sulla tua bocca lo dirò, quando la luce splenderà!
Ed il mio bacio scioglierà il silenzio che ti famia!
Chorus: Il nome suo nessun saprà, e noi dovrem ahimè, morir, morir!
Dilegua, o notte! tramontate, stelle! Tramontate, stelle!
All'alba vincerò! Vincerò! Vincerò!
O Soave Fanciulla
Opera La Bohème (prem. 1896)
by Giacomo Puccini (1858-1924). Seq. Bill King, at Aria Database.
[ Rudolfo — Mimi ]
O soave fanciulla,
O dolce viso di mite circonfuso alba lunar,
In te ravviso,
Il sogno ch'io vorrei sempre sognar!
Fremon già nell'anima, – Ah, tu sol comandi, amor!
Le dolcezze estreme. – Tu sol comandi, amore!
Fremon nell'anima, – Oh, come dolci scendondo!
Le dolce estreme, – Le sue lusinghe al core.
Fremon dolce estreme,
Nel bacio freme amor! – Tu sol comandi, amor!
Oh, Danny Boy
Music: Melody trad. Londonderry Air, (c. 1851).
Lyrics: Frederick E. Weatherly, 1910. Seq. (instrumental) Barry Taylor.
Oh Danny boy, the pipes, the pipes are calling
From glen to glen, and down the mountain side
The summer's gone, and all the flowers are dying
'Tis you, 'tis you must go and I must bide.
But come ye back when summer's in the meadow
Or when the valley's hushed and white with snow
'Tis I'll be here in sunshine or in shadow
Oh Danny boy, oh Danny boy, I love you so.
All Through the Night
Music: Melody trad. Welsh folk song.
Seq. Modified from Anonymous at ingeb.org.
Sleep, my child, and peace attend thee
All through the night.
Guardian angels God will send thee
All through the night.
Soft the drowsy hours are creeping,
Hill and vale in slumber sleeping.
I, my loving vigil keeping
All through the night.
Plaisir d'Amour
Music: J. P. A. Schwarzendorf (1741-1816).
Lyrics: J-P Claris de Florian (1755-1794). Seq. Laurier Nappert.
Plaisir d'amour ne dure qu'un moment;
Chagrin d'amour dure toute la vie.
J'ai tout (Tu m'as) quitté pour l'ingrate (la belle) Sylvie;
Elle me (te) quitte et prend un autre amant.
Plaisir d'amour ne dure qu'un moment;
Chagrin d'amour dure toute la vie.
"Tant que cette eau coulera doucement
Vers ce ruisseau qui borde la prairie,
Je t'aimerai," me (te) répétait Sylvie;
L'eau coule encore, elle a changé pourtant.
Plaisir d'amour ne dure qu'un moment;
Chagrin d'amour dure toute la vie.
The Foggy, Foggy Dew
Traditional English folk song.
Seq. to be announced.
When I was a bachelor, I lived all alone, and I worked at the weaver's trade,
And the only only thing that I ever did wrong was woo a fair young maid.
I wooed her in the wintertime, the spring and summer too,
And the only only thing I ever did wrong was To Keep Her From The Foggy, Foggy Dew.
One night she came to my bedside, when I lay half asleep.
She put her head upon my bed, and she began to weep.
She sighed, she cried, she damn near died, she said, What shall I do?
So I took her into bed, and I covered up her head, just T.K.H.F.T.F.F.D.
Once again, I'm a bachelor, I live with my son, and we work at the weaver's trade.
And every every time that I look into his eyes, he reminds me of the fair young maid.
He reminds me in the wintertime, the spring and summer too,
Of the many, many times that I held her in my arms, just T.K.H.F.T.F.F.D.
Exsultate Justi
Ludovico di Viadana (1564-1645).
Seq. from music at CPDL.
Note: The lyrics are repeated numerous times in counterpoint.
For simplicity, these are the minimal lyrics:
Exsultate justi in Domino, rectos decet collaudatio.
Confitemini Domino in cithara.
In psalterio decem chordarum.
Psallite illi.
Cantate ei canticum novum.
Bene psallite ei in vociferatione.
Exsultate justi in Domino, rectos decet collaudatio.
* Thanks to Jeroen Wijering for the music player code. *