No, MakeMusic did not make a VST3 Multi version of the ARIA plug-in. 

Thanks. That's too bad.

Although it can be easier to host a whole brass section (or similar) in one VST, there's not really any disadvantage in having each instrument in a separate instance. (The ARIA reverb for all instruments in a Multi comes out on channel 1/2, so that's a potential problem.)

There is a VST3 Multi plug-in on the Mac version: it's unclear why they didn't include it on Windows.

Interesting point about the reverb. I had been sending each instrument out to a different channel in the mixer and using third-party reverb plugins, so I never thought about the limitation on ARIA reverb.

I periodically wonder if I should move on from ARIA since Garritan is not updating its products, but then I think about the awesome value Garritan offers (i.e., low price and generally high quality) and I stick with it.

My own view is that Garritan strings and brass are pretty poor -- they suffer from incomplete playing styles and a lack of realism in the sound. But woodwind and most single-strike, single-sound instruments are excellent -- Timpani, Glockenspiel, and most percussion; Piano, Organ, Harp, etc. 

Also the ARIA platform is fantastic. The ability to create and edit instrument definitions -- how the samples are played -- using human-readable text files is brilliant. I've fixed many 'errors' in GPO5, and created my own new instrument definitions using the Garritan samples. There are other SFZ instruments and libraries out there, many of them free.

Plogue continues to develop the ARIA engine as part of their Sforzando player, which also plays the Garritan libraries. They are working on a 'next-generation' replacement. If MM's ARIA Player becomes unsupported (and there is very little evidence for support right now), then Garritan SFZ files should keep working on Plogue's software.

Ben:  Thanks, and I agree with your comments. I hadn't previously thought of looking at other SFZ instruments, but I will do so now.