The guitars designed by Mario Maccaferri and the Selmer Company are some of the most unique instruments made in the last century. They are an ingenious combination of flat top and arch top guitars with some of the qualities of both. They were originally built early in the jazz age when guitars of greater volume and projection were necessary in order to be heard over the wind instruments typical to jazz ensembles. Guitar manufacturers in this country like Gibson and Epiphone were developing the arch top design that produced a mid-range dominant tone that had the volume and cutting power necessary for live playing situations, but these were rare and very expensive in Europe. Mario Maccaferri’s design produced a guitar with many of the same qualities of tone at a fraction of the cost. While these are magnificent instruments in their own right, I contend that we have learned a few things since 1930 that can be incorporated in Mario’s design to make it better serve the player in the 21st century.
Mario Maccaferri was a classical guitar performer and luthier who studied with builder-musician Luigi Mozzani in Cento, Italy. (Francois Charle, The Story of Selmer-Maccaferri Guitars). The instruments he built with the Selmer Co. were influenced by this tradition, but Mario was always an independent and creative thinker. He designed several models for Selmer, but the two that have become most popular) thanks to celebrity endorser Django Reinhardt) are the Orchestre Model – known as the Model Jazz or Grande Bouche- and the Selmer Model known as the Petite Bouche. Mario’s major innovation on these guitars was the use of a highly domed top that allowed the bridge to be of sufficient height so that a tailpiece could effectively be used.
The primary movement of a floating bridge under string tension is vertical, with very little torque or rock, which is why the tone is mid-range dominant. The wide, glued on bridge of a flat-top guitar is driving the soundboard in a more complex way that favors fuller overtone development. The amount of down-pressure on the bridge greatly affects both tone and volume. Greater load favors the fundamental pitch and more volume, while lesser load makes for a richer tone with more harmonic overtones but somewhat less volume. I build my tailpieces with height adjustment screws that allow the player to balance the instruments fundamental/overtone mix by changing the break angle over the bridge. Bridges on these guitars are hollowed out to reduce mass and increase volume. Players today prefer much lower action than in the past, so it is sensible to make the bridge with an in-set saddle for easy adjustment to various string attack.
The dome shape of the top is crucial to the tone and functionality of this kind of instrument. This dome is accomplished in Maccaferri’s design by gluing arched braces to the top that run perpendicular to the grain of the spruce with two short vertical braces under the bridge. This creates a cylindrical section, with the entire arch in one plane. Forcing the top down at the neck and tail blocks attains the dome, which creates a lot of uneven stress on the top. The back is built in a similar way – like most modern flat tops. The tone of these guitars is predictably dry and lacking in overtones. In my experience, ladder bracing favors the fundamental pitch of any note at the sacrifice of the rest of the overtone range. I believe this is because the top is divided by the braces into only a few essentially rectangular vibrating plates. Ladder bracing is used in lute construction, but gluing the braces slightly off parallel ameliorates this problem.
A better solution in my opinion is to X brace both the top and the back. This creates the compound-complex dome in one setting, with minimal stress on the glue joints of the neck and tail blocks. This allows more of the plate to be free to move as a unit – the trampoline effect. Additionally, breaking the soundboard into more odd sized areas encourages fuller overtone development. It is necessary to support the bridge with additional X bracing under the tails to prevent collapse (discovered the hard way). I like to brace the upper bout solidly to support the fingerboard end for clearer high note playing. It helps to think of the bracing as creating a top with graduated thickness like a violin or arch top guitar.
X bracing the back has the effect of re-enforcing bass response considerably, both in this style guitar and in regular flat tops. When all the tension of the arch is held by the braces, the back is able to pump air more freely and efficiently. I like to add a cross brace between the X in the lower bout for extra support. The tap tones are very lively with a back braced like this. The backs of Selmer-Maccaferri guitars were laminated, but using solid woods is clearly an improvement.
I use a sanding dish that allows for a 5/16" arch to sand the interlocked XXX top braces as a unit. They can then be easily go-barred to the prepared soundboard in the same dish using paper as a pad. Using more arch risks splintering the plate from too great a stress (the hard way again). The rib assembly can be shaped for a perfect fit in the sanding dish too. Rough plane the sides before the linings are attached using the sanding dish as a pattern. A 4 ½ degree angle on the blocks is about right to accommodate the dome. Don’t forget to make a side pattern for the next time once you’ve got it right. With the ribs in the mold, rotate on the sandpaper until sanding marks appear on all the linings and end blocks.
The Grande Bouche (Big Mouth) model has much more mid-range tone than a good flat top guitar, but it is considerably more rich than a good arch top guitar. The original had a 12 fret neck, and was preferred for rhythm playing. Most modern makers have given it a 14 fret neck for practical reasons. My "Model Manouche" has a broader tonal spectrum than ladder braced instruments, and is more versatile in its uses. The Petite Bouche (Small Mouth) model has a long 26.25" scale and is preferred for solo playing. The tone is more treble, being closer to an arch top guitar. I have been putting a sound port on the upper bass bout that has opened up the tone of this guitar considerably. Not only can the player hear the instrument better, it has allowed the box to breath, and increased volume and responsiveness. That little hole is cute, but it’s just not big enough to let the sound out. I think sound ports are as close as we get in this world to something for nothing! My "Model Eclipse" is very open toned and is capable of a wide variety of tone colors.
Selmer-Maccaferri guitars are unique in the world of guitars and deserve to be toyed with and improved by us – arguably the best luthiers of all time - while maintaining the basic character of the instrument. Would Mozart have used a harpsichord today? The demands of the modern player sometimes pull us toward change, but often our innovations set a new standard for the musician.
Lehmann Stringed Instruments
34 Elton St.
Rochester, NY 14607
e-mail: Bernie @Lehmannstrings.Com