For MIDI (since RealTracks are audio and don't respond to note changes, only chord changes), for just figuring out what something is going to sound like, the best bet is a General MIDI softsynth. BIAB will send it the correct commands to use the specified instrument on the correct channel (a MIDI port can support 16 channels of MIDI data).

You mentioned Sonar, so if you have Sonar installed, you may be already have the TTS-1 DXi synth; if not, it comes bundled with (what used to be Cakewalk Music Creator - not too expensive - but now called Sonar Home Studio, as well as the bigger brother versions of Sonar). You can get some sounds using the Microsoft sound set, but it's not very good (and the Coyote WT that comes with BIAB just takes those sounds and presents them to you as a DXi softsynth. Better is the Coyote Forte, which is $40 (last I checked). There are also some soundfont based solutions, but this is by far the easiest ways to get some sounds out of BIAB. It'll range from poor (Coyote WT) to alright (the TTS-1 or the Coyote Forte).

Then once you decide you want to work more on the song and make it sound better, you can use something like Garritan (which uses the Aria Player) or Kontakt instruments or IK Multimedia Sampletank. The difference here is that they are not plug and play. They do not respond to the MIDI instrument or channel selected within BIAB. So you have to set the track to use one of them, then go into its interface and select from its instrument list (which won't be the General MIDI standard) and possibly have to match the BIAB output channel to the instrument's input channel. But once done, you can save that and that track will sound much better. You can also load instruments with the new Sforzando player shipping with BIAB. Lots of options, but a little more work, but once saved will sound pretty good.

If you go the Sampletank 3 route, make sure you also get the jBridge utility from PGMusic, since ST3 is 64-bit only.

There are a couple of gotchas that will affect the instruments you use. The Garritan instruments to not respond to volume changes, but instead change volume via the modulation wheel. Also, you will have a hard time getting any vibrato out of the instruments, because while many use the mod wheel for vibrato, Garritan uses keyboard aftertouch, which you would have to program in on a note by note basis using the event list editor.

Also, when using 3rd party libraries, as they get larger, you have to wait for the instruments to load before you get proper sound. This can take anywhere from a few seconds to a minute or longer, depending upon how many tracks and how much data has to get loaded into memory.

Don't know if this helps.

John

Laptop-HP Omen I7 Win11Pro 32GB 2x2TB, 1x4TB SSD
Desktop-ASUS-I7 Win10Pro 32GB 2x1.5TB, 2x2TB, 1x4TB SATA

BB2025/UMC404HD/Casios/Cakewalk/Reaper/Studio One/MixBus/Notion/Finale/Dorico/Noteworthy/NI/Halion/IK

http://www.sus4chord.com