Tom Saputo at "Open Mic" piano bar at Squire Rockwell's - Annandale, Virginia.
A piano bar (also known as a piano lounge) consists of a piano or electronic keyboard played by a professional musician, located in a cocktail lounge, bar, hotel lobby, office building lobby, restaurant, or on a cruise ship. Usually the pianist receives a small salary plus tips in a jar or basket on or near the piano, especially from patrons requesting a song traditionally written on a beverage napkin. Some piano bars feature a baby grand or grand piano surrounded by stools for patrons (or, somewhat humorously, an upright piano covered by a counter that makes it appear to be a grand piano). Others have a bar surrounding the piano or keyboard.
Theatre historian John Kenrick describes the piano bar as follows:
"A piano bar is a hybrid creature: part performance space, part living room, part cruise-a-thon, and part saloon. The bar is there to sell drinks, the pianist is there to perform, and the crowd is there to sing, listen, drink and socialize. All of this means that it's impossible to predict what a given evening's chemistry will be, even if most of the people on hand are regular customers.... While every factor counts, the most important issue is the person at the piano. The pianist determines the type of music, the style of performance, and the general tone of the evening.... The experienced piano bar player knows how to take genial control of most any situation and generally keep the party going".
"instrumental only": the professional piano/keyboard player plays strictly instrumental music, which is usually classical, semi-classical, or "easy listening"; this type of piano bar is often found in hotel lobby lounges or "fine dining" restaurants and upscale bars.
"only the musician sings": the professional piano/keyboard player sings to his/her accompaniment, usually on microphone, but no other singers are generally allowed. Examples include Carousel Piano Bar & Lounge.
"the musician and waiters sing": the professional musician sings and also invites waiters to sing solos.
"sing-along": patrons surrounding the piano/keyboard sing as a group, usually without microphones, often preferring "standards" and "show tunes", or very old songs like "Down By The Old Mill Stream", "Bicycle Built For Two", etc., but in some cases pop or rock. It is " a social venue for singing". Examples include "Marie's Crisis Cafe" and "The Duplex" in Greenwich Village.
Postcard from Pat O'Brien's Bar in New Orleans showing the dueling pianos format
"open mic": individual patrons sing (on microphone) to the accompaniment of the professional musician; in some ways, this type of piano bar is like karaoke, except that the music is live and dynamic, and there are usually no lyrics available (although some piano bar players do supply some lyrics); like karaoke, the songs performed may cover a wide, eclectic range ("show tunes", "standards" from the 1920s forward, jazz, country, R&B, rock'n'roll, blues, folk, soul, disco, hip-hop, etc.); the patron singers are usually called to the microphone in a rotating order; often, each singer is allowed 2 or 3 songs each time he/she is called to perform. The Alley in Oakland, California, uses this format.
"combination": some piano bars include the characteristics of two or more of the above, either on different nights or combined on the same night. For instance, at a "sing along" piano bar, a patron or wait person might sing a solo from time to time.