If you play bottle neck slide style or Hawaian music you want a tricone. These guitars have a sustain that is like playing electric slide. The three cones set up a harmonic vibration that gives this unique sustain and an effect that is similar to an inbuilt in reverb unit. The single cone is ideal for jazz, jugband music, delta blues and just about anything except introspective naval gazing stuff. These guitars are LOUD, great for busking.
All styles can be in either brass or steel.
Steel has a more cutting, slightly nasal sound typically found in delta blues while brass has a more rounded tone. Brass gives a better plated finish. The Donmo Resonator Mandolin retains all the tonal qualities of a wood body mandolin but delivers an incredible volume, allowing the player to use a subtlety not possible with a standard instrument and still be heard easily in a band situation. No longer will the banjo and fiddle have to back off when you'r taking a solo.