Gondoliers have long had a reputation for serenading their passengers (except perhaps the mayor during official public events). Gondoliers originated the barcarole or "boat song" with a tempo well suited to rowing, but they have readily adopted any and all songs popular with tourists such as the Neapolitan favourites O Sole Mio and Santa Lucia..
Source:
The Mayor of Venice and his uniformed gondoliers. Photo by Gribayedoff.
Outing magazine, vol. LI no. 6, March, 1908, p. 658.