An open mic or open mike (shortened to "open microphone") is a live show at a venue such as a coffeehouse, nightclub, comedy club, strip club, or pub, usually at night, in which audience members may perform Stages whether they are amateur or professional, often to promote a debut or upcoming performance, the performers, as the name suggests, are usually plugged into a PA system so that they can be heard by the audience.
Open mics may have little or no admission, although the venue itself may set up a gratuity jar, "pass the hat" for charity, or a raffle with various prizes. Places that don't charge a fee make a profit from selling alcohol and food. Performers are generally not paid, although the venue may provide them with drinks or food.
If the host is an experienced professional and not the owner/manager of the venue, they are usually paid for their services and may perform at any time during the evening, either by preparing their own full performance or fill in at short notice when a performer is unavailable. Open mics are somewhat related to jam sessions, in that they both involve giving amateur artists the opportunity to perform. The difference is that jam sessions often involve a musical group, possibly even a house band or rhythm section, and may include the participation of professional artists.