Cover acts or bands are entertainers who perform a broad variety of crowd-pleasing cover songs for audiences who enjoy the familiarity of hit songs. Such bands draw from either current Top 40 hits or those of previous decades to provide nostalgic entertainment in bars, on cruise ships and at such events as weddings, family celebrations and corporate functions. Since the advent of inexpensive computers, some cover bands use a computerized catalog of songs, so that the singer can have the lyrics to a song displayed on a computer screen. The use of a screen for lyrics as a memory aid can dramatically increase the number of songs a singer can perform.