Style O

National introduced the Style O in 1930. Before amplifiers were everywhere, the problem with a guitar was volume, and National’s answer was to put a cone inside the body, a thin aluminum disc that works like a loudspeaker. The strings sit on a saddle set into a wooden “biscuit” in the middle of the cone, and the cone throws the sound out. The Style O has one cone. Some Nationals have three.

The body is metal. The very first Style Os were nickel-plated steel. Very soon they were brass, plated in bright nickel, with a Hawaiian scene sandblasted into the finish. It’s a flashy-looking thing. In late 1934 or 1935, depending who you ask, the neck moved to join the body at the 14th fret. The original run ended in 1941. Nobody counted them, but the serial numbers suggest “well over 5,000.”

Pick one up and the first surprise is the weight. A modern one comes in at close to nine pounds, and the body is cold under your arm in a way no wooden guitar is. The neck is maple with an ebony board, the scale is a hair shorter than a Martin’s, and the sound comes straight at you: bright, loud, a little metallic, with a quick, snappy attack. Play it with a slide and you’ll understand the whole idea in about four notes.

Resonators get mixed up constantly, so here’s the short version.

A Dobro is a different company. John Dopyera left National to start it, and Dobros have wooden bodies and a spider bridge instead of a biscuit. A Duolian is a National, but the cheaper one: painted steel, no nickel, no Hawaiian etching. A tri-cone is a National with three cones. The Style O is the nickel brass one with a single cone.

The old blues players are where it gets slippery. There are photographs of Son House and Bukka White holding Style Os. That’s real. But a photo isn’t a session log, and it doesn’t mean every record they made is this guitar.

Today National Reso-Phonic builds Style Os in San Luis Obispo, California, in 12-fret and 14-fret versions. The 12-fret one has the slotted headstock and the older look. The 14-fret one is Knopfler’s kind. There’s even a Weathered Steel version for people who like their resonators looking like they spent the ’30s on a porch. It’s a revival, not a straight line from the 1930s factory, but it’s the same idea: brass, nickel, one cone.

When Knopfler sold a lot of his guitars at Christie’s, he kept this one out of the sale. After all the guitars he’s bought and played and let go, the shiny one from the album cover is still his.