Petit extrait d'un site (Sheehans.com) :
Citation:
Most guitars can be categorised as one of 4 basic shapes.
1. Dreadnought
This is the classic acoustic guitar shape developed in the 1920's by the Martin Guitar company, and even today, probably 75% of acoustic guitars are derived from this design. Square in shape, the large body gives plenty of volume and projection, but the wide 'waist' tends to make dreadnought guitars feel relatively bulky when rested on the knee, and some smaller players (particularly women) find them uncomfortable to play.
2. Grand Auditorium
Rapidly becoming the best selling guitar shape. The larger body is good for depth of tone, the narrow waist makes it very comfortable. This shape gives great balance between bass and treble, making it a good choice for an Electro Acoustic, and adapts well to Fingerstyle as well as Strumming styles. The Grand Auditorium is very versatile, and is often the perfect shape for a player who wants one guitar to fulfill all their requirements.
3. Grand Concert (Small bodied / Folk size)
As well as having a small body size, these guitars are often fairly shallow in depth. They are often still surprisingly loud, but unless they are in the higher price range, usually do not have such a warm tone as their larger cousins. Preferred by some smaller players, who find them more comfortable, the tone of small bodied guitars - often described as "tight", "springy", "lively" or "bright" - also makes them a popular choice for ragtime and fingerstyle blues players.
4. Jumbo
The largest of the standard shapes, with a big, deep open sound favoured by many for country styles. Made famous by Gibson, whose model J200 was used in the 50's and 60's by some of the greats, including Elvis Presley and the Everly Brothers.
Edit : Petit ajout... en français et assez bien détaillé.
Je tiens néanmoins à souligner que chacun a son avis à propos de la forme la plus polyvalente... Perso je pense que la grand auditorium est le meilleur compromis entre encombrement / basses / clareté.
