Martin Custom Shop OM Auditorium 28 Style Acoustic Guitar, Adirondack Spruce/Sinker Mahogany

Martin Custom Shop OM Auditorium 28 Style Acoustic Guitar, Adirondack Spruce/Sinker MahoganyThe Martin Custom Shop OM Auditorium is built on a blueprint that helped shape the American acoustic guitar as we know it. Originally introduced in the early 1930s, the Orchestra Model (OM) combined a 25. 4" long scale with a 000 size body, creating a platform that became a staple for fingerstyle players, session musicians, and soloists alike. This particular Custom Shop build updates that formula with both subtle refinements and choice materials hand

The Martin Custom Shop “OM” Auditorium is built on a blueprint that helped shape the American acoustic guitar as we know it. Originally introduced in the early 1930s, the Orchestra Model (OM) combined a 25.4" long scale with a 000-size body, creating a platform that became a staple for fingerstyle players, session musicians, and soloists alike. This particular Custom Shop build updates that formula with both subtle refinements and choice materials hand-selected through Martin’s long-standing partnership with Russo Music as an Expert Dealer.

The body features a bound Adirondack spruce top paired with Russo Music–selected premium sinker mahogany back and sides. Adirondack has long been favored for its high stiffness-to-weight ratio, while sinker mahogany, recovered from riverbeds, has earned a reputation more for its provenance than any unverifiable tonal mythology. The 1/4" Golden Era scalloped X-bracing (also Adirondack) is forward-shifted, offering a structural design historically associated with pre-war Martins.

The neck is carved from select hardwood and shaped to the GE Modified Low Oval profile with a High Performance Taper. This design balances vintage shape with modern playability. A long diamond volute nods to Martin’s legacy neck construction. The ebony fingerboard features a 16" radius and is adorned with Diamonds and Squares Long in abalone—a high-end twist on the traditional 28-style aesthetic. Standard 20 frets and a 1 3/4" bone nut round out the specs.

There’s no onboard electronics, a decision that reinforces the purist build philosophy. The finish pairs an antique toner top with a gloss body and satin neck, giving this OM both presence and playing comfort. Herringbone top inlay, HD Zig Zag purfling with black accents, and Grover open-gear tuners complete the visual and functional package.

This guitar is a reflection of what the Martin Custom Shop does best: honoring tradition while executing each detail with precision. A Custom Shop OM from a shop that knows the difference.

• OM Auditorium body w/ 25.4" scale length
• Adirondack spruce top w/ antique toner
• Premium sinker mahogany back and sides
• 1/4" Golden Era scalloped X bracing
• GE Modified Low Oval neck w/ volute
• Ebony fingerboard w/ abalone inlays
• Grover open-gear vintage tuners
• No electronics; traditional acoustic build