I was looking for some free singing speech-synthesis software the other day, reading this post from EM411. There doesn't seem to be much for PC, but Vocal Writer does the job very nicely for free ($39 shareware), and it's just been updated to OSX. Listening to this [mp3] sample of the thing singing 'Penny Lane' made my day, and I spent some time fiddling with it at work. It sounds almost exactly like a very badly edited spoken-word recording fed into a vocoder.
Posted by Tom Whitwell.
Comments:
Vocal writer can be heard extensively on Simon Postford and Raja Ram's 3 Shpongle albums.
'Virtual Singer' which comes as part of the shareware "melody assistant' from http://www.myriad-online.com/en/index.htm Is great too... It's got a lot of options, you can make some pretty weird voices.... or some fairly (by speech synth stadards!) realistic ones
also you can actually make a synth voice from your own speech!!! Tho it seems a pretty complex process... I haven't really tried yet but could be interesting!
I actually bought 'melody assistant' just for the virtual singer but haven't really got round to doing much with it other than running some Kareoke midi files through it to amusing effect!
Check out also Talk Back to Basics from Man or Astroman? collaborators ORI. It allows you to play the Mactalk voices as instruments... you can assign different phrases at different pitches and play using the mac keyboard... fun... they have various other strange audio apps for mac and windows too: http://www.wizardmaster.com/bludgeonsoft/audio.html
I know you were looking for a free vocal synthesizer, but you might want to check out Yamaha's Vocaloid, which is the best vocal synth I've seen. The Japanese demos on their site aren't too convincing, but I did a pop song in english that shows how dynamic and realistic the voices can be. http://www.bunk9.com/doubleclick/