In the early 20th century, arched-top or archtop guitars won out over the banjo and flat-top guitars thanks to their greater volume and ability to "blend" better with the rest of the band's instruments. They usually took their place alongside the rhythm section, and taking on the role of solo instrument would be a slow process, until pickups were added; to this day, it has been the standard instrument for the vast majority of jazz guitarists.
The arrival of the first electric guitars caused archtop sales to drop drastically, relegating the instrument to a small circle of jazz guitarists and a handful of builders. It wouldn't be until the nineties that interest in these guitars became more widespread.
I won't go into historical details about builders and players, since there's already plenty of information available, but the following builders' names are benchmarks. D'Aquisto, successor to D'Angelico (1905 – 64), is one of the most prominent. The early Epiphones and Strombergs, as well as Gibsons, are the instruments on which most of the great jazz guitar recordings of the last century were made. Today there are a great many independent builders, perhaps the most famous and longest-established being Benedetto; likewise, Linda Manzer, a Canadian luthier whose regular clients include Pat Metheny, is one of the most prominent names among the builders of these instruments.
The body of this type of guitar is closer to bowed string instruments than to the Spanish or acoustic guitar: both the top and the back are carved from two pieces of quartersawn wood, wedge-shaped and with the grain perpendicular to the surface, as is usually done with violins. It has no soundhole and instead has two "F"-shaped holes on either side of the top. The strings are anchored to a tailpiece, which relieves the top of much of the tension, and the bridge, which isn't glued, rests on two "feet," another feature shared with violins.
The bridge is taller than on traditional guitars, and the neck is set at a steeper angle to compensate for the greater string height above the top.
Quality guitars of traditional construction have a carved spruce top, along with sides and a back, also carved, of maple. Cheaper mass-produced guitars usually have a laminated maple top and back, and an internal block running from the tail to the neck heel to minimize feedback. Although these guitars don't have much in common with a genuine archtop, with a good choice of pickups they can sometimes produce an amplified sound with a character halfway between a Les Paul and a true archtop, but one that certainly has nothing to do with a guitar like the one I described above, properly amplified.
There are also options which, in order to cut costs, use high-quality laminate only for the back while respecting traditional construction. These are worth considering because, for a more affordable price, we can have a guitar as close as possible to the real thing, which sometimes has little to envy, if we're lucky enough to get the "good" spruce top in the run.
Several factors, apart from the materials used for the body, play a very important role in the final sound. On high-end guitars, drilling holes in the top to install one or two pickups is a big mistake, because these are guitars built to get the best "unplugged" sound, and doing so would only diminish the acoustic properties of the top. The usual method for installing a system to reproduce the guitar's sound is to mount a floating pickup attached to the end of the fingerboard, with the volume and tone knobs on the pickguard, which is also suspended over the top. The price of these guitars can reach breathtaking amounts, but their construction process is the most laborious and complicated of any type of guitar. The tailpiece is another important element: metal ones are the most common, but carved ebony ones are usually used on high-end instruments, and some builders have made tailpiece making not just an art, but a science. Most of what has been discussed so far applies only to the highest-end instruments, which only a privileged few can afford; but there's one element common to cheap and expensive guitars alike: the bridge. The material used for the bridge, as well as its correct fit, are parameters to take very seriously. An ebony bridge, with its feet properly resting on the top, will give us a better response than one made of softer wood and poorly fitted.
A common problem with this type of guitar is an audible difference in volume between strings and/or notes. When the bridge feet don't rest completely on the curved surface of the top, small gaps are left that keep the string vibration from being transmitted properly; generally, the low frequencies suffer most from this. Sometimes this poor fit between the bridge and the top is almost imperceptible and hard to notice. It's incredible what fixing this problem can do, even on the cheapest guitars. Of course, finding this problem on a luthier-built guitar would be unacceptable, unless it were an old instrument whose top had warped slightly after years of use, a repair that's commonly done even on the most prized violins.
Another very important factor is string gauge. In general, this type of guitar tends to appreciate heavy gauges (.012 / .052 and up), but sometimes it's very worthwhile to experiment with hybrid gauges, since going up a gauge on a particular string can give us a more balanced response.
One of the "drawbacks" of these guitars is how poorly they adapt to musical styles other than jazz. However, guitars with smaller bodies, maple tops and backs, an internal block and two pickups can indeed be taken into other territory, such as rockabilly, pop, blues, rock and fusion, but as I said above, they're a different kind of guitar. Unless you devote yourself entirely to jazz, perhaps the smartest choice is to get a guitar like the ones I've just described; most of them are based on Gibson's famous 335 model, with Ibanez models probably being the most popular. That said, the experience of playing an archtop with a spruce top and a body bigger than a Jumbo is another dimension. To give an example, it's like the difference between playing an amplified thin-body Spanish guitar, even one of the best, and playing a concert guitar; the feel of the vibration and the richness of harmonics is an incomparable sensation. Mind you, getting that sound amplified on a stage is another matter, not to mention the fingernails!!!
If choosing a guitar is hard enough on its own, there's still the amp, the pickup and the pick to choose. It's not unusual to see top-level guitarists playing through small solid-state bass combos and using picks so thick we didn't think they existed. The jazz guitar also has six strings, or seven, but it's another kind of animal that calls for very different treatment from the electric or acoustic guitar. As always, looking at what gear established guitarists use is a good starting point. Here, unlike electric guitar rigs, the number of components is smaller. After that, all that's left is to practice a gazillion hours and ask ourselves: how on earth do they do that?