I've built around 10 Joomla sites and have worked with HTML and CSS (not js or php in any depth though) for about 10 years, and I've just been asked to build a couple of music/audio sites in Joomla.
It's remarkable to me how few decent html5 audio extensions there are available. I've tried a few audio players, but with Flash appearing to be in its twilight years (as far as mobiles etc are concerned) none of them really did the job I wanted on all devices.
Enter the SJ HTML5 Audio Player. See, not only is this a great player, beautifully styled as default (and style-able), it's also simple to implement and use. However, if you're an awkward beggar like me, the superjoom team will help. Did I say 'help'? Waaaay above and beyond the call of duty. The team worked for the better part of a day trying to accommodate a request I made, respectfully and with no complaint throughout.
From what I gather, whatever limitations the player might have right now will be addressed in future upgrades, so they're clearly not a static bunch of developers either. The instructions are fairly non-existent, but then again, you don't need much instruction to use it from scratch.
I'm very wary of putting even a small amount of money down for paid extensions. The SJ HTML5 Audio Player was worth many times more than I paid for it and I only wish I could give it and them 10 stars.
Superb after-sales service for a product that's pretty near perfect to begin with.