Wiktionary
n. A comical or nonsensical song, usually performed for comedic or humorous effect.
Wikipedia
A novelty song is a comical or nonsensical song, performed principally for its comical effect. Humorous songs, or those containing humorous elements, are not necessarily novelty songs. The term arose in Tin Pan Alley to describe one of the major divisions of popular music. The other two divisions were ballads and dance music. Novelty songs achieved great popularity during the 1920s and 1930s. They had a resurgence of interest in the 1950s and 1960s.
Novelty songs are often a parody or humor song, and may apply to a current event such as a holiday or a fad such as a dance or TV programme. Many use unusual lyrics, subjects, sounds, or instrumentation, and may not even be musical. For example, the 1966 novelty song " They're Coming to Take Me Away, Ha-Haaa!" has little music and is set to a rhythm tapped out on a snare drum and tambourine.
A famous book on achieving an attention-grabbing novelty single is " The Manual (How to Have a Number One the Easy Way)", written by The KLF. It is based on their achievement of a UK number-one single with " Doctorin' the Tardis", a 1988 dance remix mashup of the Doctor Who theme song released under the name of 'The Timelords.' It argued that (at the time) achieving a number one single could be achieved less by musical talent than through market research, sampling and gimmicks matched to an underlying danceable groove.
Usage examples of "novelty song".
A novelty song of the same name was in stores within four days of the Event, and available for download on some internet sites in two.
Flood (the former Arthur John Beauchamp) has been playing the novelty song at least sixteen times a day since the record was released on October 1 i.
Toby was irresistibly reminded of the old novelty song about a whole bunch of mice who lived in a windmill in old Amsterdam.