Jigs and reels hail from the Irish (folk) music repertoire. Both of these forms of music can be danced to.
Very simple in structure, and very hummable, many of the Celtic jigs and reels are extremely catchy and can stick to your head for a while once you hear them.
While a jig is in 6/8s (fast paced trisram – or catursra eka talam in trisra gati), the reel is in 4/4 (fast paced catursram – or catursra eka talam in catursra gati).
A waltz is slow, but a jig is fast paced.
The same melodic pattern would repeat over and over again – with slight variations.
A good example of a jig could be seen in the film Titanic in the pub scene depicting a spirited dance.
Celtic music refers to the music of Ireland/Scotland.
Instruments used commonly in this tradition include the flute, the pennywhistle, the fiddle, the guitar, the celtic harp and of course the bagpipes.
Instruments play solo as well as in ensembles. When a guitar is present, it provides the harmony; else all instruments play in unison. The loose nature of the rules allows for variations. The music is not written down necessarily and much is played by the ear.