It's amazing how much of what 'we know' about the Navy in Nelson's time is what we've heard. Unfortunately this also includes the guides on Victory, who seemed to be not well-trained, or at least weren't when I last visited (sorry Georgie-Peorgie, they may be an excellent navy, but their knowledge of history is patchy). Three rounds in five minutes was thought to be an excellent rate of fire. Three in a minute was impossible.

I believe there was at least one recorded occurrence of dancing before a battle (in light airs and an approaching speed of 1 or 2 knots it could indeed take quite some time to be within gun range, say 1,000 yards), but this was probably taken up by the many writers of naval fiction so it seems to have been more widespread. Captains varied greatly in their approach to discipline. Dancing would be limited to the forecastle or upped deck. Dancing on other decks should be limited to the severely vertically challanged.

It's also worth pointing out that, compared with merchant ships, warships had crews that were far more than they needed to simply sail the ship (six to ten times more in number). You could clear for action in about five minutes. In most accounts any time before the ship came into range was taken up by sending the hands to dinner. Most Captains made sure that their crew had a hot meal before an action if there was time.

Music on board - depended very much on circumstance. Some Captains employed a whole band, but mainly to play for the officers. Sometimes a sailor would be a capable fiddler, or a Marine drummer could play a fife (Marine Drummers were adult, not like the army's drummer boys). Most ships could muster some sort of music. Incidently, the fiddler in the 1984 film about the Bounty (the Mel Gibson/Anthony Hopkins one) is none other that Barry Dransfield.

And it was normally lemons as the citrus juice available at this time. Lemons were much more readily available in Europe.