These songs might be pedestrian (heh) to you, but there is so much niche and experimental all using the same voice--I find this highly fascinating.
The above songs I think give a pretty wide longitudinal view of Vocaloid music and the variety you can find in the fandom, from just Hatsune Miku as the vocal.
Also adding: a couple of imageboard originals that introduced me to vocaloid, not really a fan of most vocaloid music though. I still don't know what sub-genre these are -- the producers being anonymous doesn't help!
Luka(?) sounds pretty natural here, too, especially for 2009. I still remember thinking at first that it was sung by a human.
All of the examples linked so far sounds highly artificial, so much that I'm guessing part of the charm for the listeners is the artificial and robotic sound/voicing, so the producers make it extra so in order to giver higher satisfaction.
Is there any examples of songs out there going the opposite way, trying to use something like Vocaloid to make the voice and singing as realistic and human-like as possible?
Ai Dee by Mitchie M is famously tagged [Miku & Luka sing like humans] on the original upload, so that was an explicit goal. Of course, it may not sound as impressive today as it did in 2012, but it's a reasonable attempt.
Which portions specifically? Gave it a listen and didn't find any parts that came close to not sounding robotic. Maybe in comparison to the other examples linked here, that one was better (but I'm unsure if that's actually true), but if that's state of the art, I'm not sure it really comes close to hitting the mark.
Definitely not state of the art as far as being humanoid, that would be the top level link.
It's also not particularly humanoid, just closer than most vocaloids I've heard. Going off of my memory of the song, it's more the intonation then the timbre that stuck out as being more realistic.
I'm afraid I'm not willing to listen through the song currently, I usually dredge up some stuff I'm not wanting to deal with right now when I listen to this artists music.
Twitter Land - STEAKA : https://www.youtube.com/watch?v=e_qQEU_uGjw
Chimera - DECO*27 : https://www.youtube.com/watch?v=c6HKcNVbByc
Start Up! - Nariyama Ryo : https://www.youtube.com/watch?v=LFOV9NbkiJM
My name is - yanagamiyuki : https://www.youtube.com/watch?v=1hj3BDehQGc
Dance with me - Osanzi : https://www.youtube.com/watch?v=n37kZTKbpSM
Highlight - KIRA : https://www.youtube.com/watch?v=AYUNaQaDfa8
Ghost city tokyo - ayase : https://www.youtube.com/watch?v=lWl5viCqGSc
Aqua illumination - PedestrianP : https://www.youtube.com/watch?v=F02fIei8gZU
These songs might be pedestrian (heh) to you, but there is so much niche and experimental all using the same voice--I find this highly fascinating.
The above songs I think give a pretty wide longitudinal view of Vocaloid music and the variety you can find in the fandom, from just Hatsune Miku as the vocal.