The pibgorn is a Welsh species of idioglot reed aerophone. The name translates literally as "pipe-horn". It is also historically known as cornicyll and pib-corn. It utilises a single reed (Welsh: "cal", or "calaf"), cut from elder (Sambucus nigra) or reed (Arundo phragmites), like that found in the drone of a bagpipe, which is an early form of the modern clarinet reed. The single chambered body of the elder pipe has a naturally occurring parallel bore, into which are drilled six small finger-holes and a thumb-hole giving a diatonic compass of an octave. The body of the instrument is traditionally carved from a single piece of wood or bone (See photograph right). Playable, extant historical examples in the Museum of Welsh Life have bodies cut and shaped of elder. Another, unplayable instrument at the Museum, possibly of a later date, is made from the leg bone of an unspecified ungulate (See photograph right). Contemporary instruments are turned and bored from a variety of fruitwoods, or exotic hardwoods; or turned from, or moulded in plastics. The reed is protected by a reed-cap or stock of cow-horn. The bell is shaped from a section of cow-horn which serves to amplify the sound. The pibgorn may be attached to a bag, with the additional possibility of a drone, which is then called pibau cwd; or played directly with the mouth via the reed-cap.
A double-pipe (having two parallel chanters both ending in cow-horn, with a common stock) of unknown provenance, dated 1701 held by the Museum of Welsh Life has caused some controversy as to its possible Welsh or Mediterranean origin.
The pipes in Wales, of which the pibgorn is a class, are mentioned in the laws of Hywel Dda (died 949–50). The earliest transcription of these dates from 1250 and specify that "the King should recognise the status of a Pencerdd (the second in importance of the three court musicians, namely; Bardd Teulu, Pencerdd and Cerddor) in his service by giving him an appropriate instrument - either Harp, Crwth or Pipes." In modern Welsh orthography these three instruments are called telyn, crwth and phibau. Peniarth 20 (Brut y Tywysogion) c 1330, states that there are three types of wind instrument: "Organ, a Phibeu a Cherd y got", "organ, and pipes and bag music".