It happens all the time: ‘Send the piano-player a drink’.
But today, many pianists do not want a drink while they play and are also health conscious. Many prefer to say, ‘No thank you’, which sometimes is taken as an insult by the guest. But guests do not understand this, as it has been a custom for many years.
It would be better for the guest to give the pianist a tip so they have a choice of whether they have a drink or something else. In the US it is customary for a tip jar to be put on the piano, but in Europe managements look down their nose at such an idea, as they prefer to make the commission on the sale of a drink for the pianist.
In numerous hotels, the staff all but forces the pianist to take a drink even if they end up throwing it away, because the salary of the staff is often based on commission on sales and it also helps them meet their monthly budget-target.
Maybe managements feel that having a tip jar on the piano is implying to the clientele that they do not pay the entertainer enough.
STORY. I once worked a very high-class hotel and the barman gave me a single malt whisky because a customer had offered me a drink. A month later I got a letter from the booking agency stating that the hotel would not hire me again because I took a drink that cost 65sFr. It was not my fault, but the bar staff were greedy and that cost me my job, lost a customer and of course the blame fell on me.
I also worked on a cruise ship which had a regulation which disallowed tips. Passengers had to leave the tips in envelopes when they left the ship at the reception and the staff would get it later. Many guests told me that they left a tip for me and of course when I finally left the ship there were no tips for me. If you travel on a ship or in hotels please leave all tips directly to the person you want to give them to.