I don't think it can do music, I think it has like one or two sound channels that can play simultaneously, it also can only play MP3's of a certain bit rate and sample depth. I did buy and have regretted the purchase. I can't remember what formats it supports, but I have heard complaints from sound pack developers who say that this certain sound will not play in vipmud when it will in their media player. It also uses a proprietary scripting language, so no lua or python or anything like that. That being said, the ability to create triggers and stuff from the input window is kind of neat. Saving triggers is confusing to me. It involves creating them and then saving them and I honestly forget how to do it, its a clunky process. I also think that 1-10 is all you get without having to view the output window. Now, I've heard people talk about channel buffers similar to what you can do with Mushclient, but I've never seen a pack with this implemented into it so I cannot attest to whether this does work or not.
You'll be most likely to find a sound pack for VIP over any other client, so if you just want to drag and drop them into your data folder and play, its a good option, but if you want to have any say over it, develop your own sound packs, I wouldn't bother, I'd honestly go with another option. I'm partial to MUSHClient because it is very powerful, and with certain plugins like lua audio, channel history, output functions, auto retyping and others,it can become very functional, and of course mushreader to get it working with screen readers. This process of setting it up is certainly an entry barrier though, and I couldn't blame anyone for not using it just on that basis because it is a bit of work to get things running smoothly. Also, sometimes installing sound packs can be a bit of work too. VIPMUD does have MUSH beat in one aspect though, the ability to tab between the output and input windows, with MUSH, you cannot do this with tab alone, you need to add control to it. You do get the control 1-0 to review last 10 lines if you use output functions though, you also get ALT 1-0 to read the last 10 of the selected buffer if you use channel history, and then configure it for use, or if its already in a pack you use. I have a NVDA addon that puts focus into the output window, which isn't the same as the control tab window, but is the main window of the client. I personally will use NVDA review and object nav to review the window. Between this, and the control numbers for last 10, and alt numbers for last 10 of buffer, I rarely need to use the control tab window. It does come in handy though for when text is scrolling fast and it will not auto scroll you to the bottom, it will store your position and keep you there until you leave it, and then it will start updating again.
I'm a cat! What's mine is mine, and what's yours is mine to :P XD