Best for: if you just want to play files online on your computer / tablet / phone etc. However you can't download the files to play offline or to write them to a CD. A useful feature allows you to play a tricky section in an endless loop.
Click here for "Verdi Requiem" on Cyberbass
Best for: somewhere between Cyberbass and John Fletcher - you can play files online or download them. Free to try, but a donation is requested if you find them useful. Unlike all other sites here, Choralia employs a synthesised human voice to 'sing' your line - some love this, others can't stand it!
Click here for "Verdi Requiem" on Choralia
John Fletcher Music
Best for: downloading files so you can play them offline, load them onto a phone/mp3 player, or write them to a CD. (You can also play them online but it's fiddly to navigate to the files each time.)
Click here for "Verdi Requiem" on John Fletcher Music
(Requires a login - currently costs £10 to register for a year. The choir no longer has a subscription.)
Best for: ready-made CDs of your part (notes not voice). The most 'professional' of the sites mentioned here; CDs typically cost around £10. The files are also available online, but you still have to pay.
Click here for "Verdi Requiem" on Choralline.