This resource provides "midi" files which may be downloaded to your computer and played back when you wish. Each file is for a seperate voice...e.g. Soprano, Bass, etc.
Your computer may simply the files if you click on them, but will likely have to be saved to your computer then double-clicked to play.
Right click on the Voice part you wish to download and "Save Link As" to a folder on your computer.
Here's the Webpage, which also has loads of info about Midi Players for Windows Computers which also show the notes associated with the music.
The link below will bring you directly to the midi voice practice files that are hosted by the very popular Website "Cyberbass" You can just clink on the link to each voice part and here that individual voice in relations to others in the background. This is an excellent, simple, but elegant resource which also allows you to slow the pace down, speed in up or skip back a few seconds.
Again, a Cyberbass resource, as described above. But here you'll find the two main choral pieces for Vivaldi's Credo in SATB format
Here's a link to Youtube videos with a playlist of all the various parts with musical notation. I'll have to ask Ethan to tell us what note our verion is in. But here's the link for now.
Here's a link to more midi files by the same host who did the Handel midi's (above)