Tremolo Harmonica

I'm not sure whether the Hohner Band is a tremolo or an octave harp - the curved body seems identified most closely with octave harps. Either way, you have a double reed harp you'd like to recondition and play.

One thing to be aware of is that with double reed harmonicas, each reedplate has both blow reeds and draw reeds mounted side by side. Each reedplate is a complete harmonica, and the two reedplates together complement each other, with the lower reedplate either tuned an octave lower (or higher) or sightly sharp to create a tremolo effect.

In the Wiener construction (so called because it apparently originated in Vienna (Wien in German) each reed is in its own hole. The blow and draw reeds are placed side by side, with each reed separated by a partition, and the upper and lower rows are also separated. So if you want to have one blow note and one draw note in your mouth like you would in a single-reed harp you need to cover two neighboring upper (blow and draw) holes, and their lower-row couterparts as well - a total of four holes. (More on this later).

Before actually working on the harp, identify which notes don't play.

• Draw a grid of the holes on a piece of paper and mark the holes where the problem reeds are located.
• Play the upper row, then the lower row (tape off a row if needed) so that you can identify exactly which reeds have problems.
• Mark the locations of the problem reeds in the grid.

Now to work on the harp itself. First thing is getting the covers off. They're nailed on at the sides instead of the top (like a Marine Band would be). Insert he sharp edge of a knife blade under the nailed tabs and pry them up just enough to where you can grab the nail heads with pliers and pull them out. That way you avoid bending the tabs too far outward, which would make reassembly difficult. Save the nails for later re-use.

With the covers off, you can easily check for problems with draw reeds, such as broken reeds, debris blocking slots, and reeds that may have pivoted out of alignment on their rivets.

Pluck each draw reed to hear if it sounds. Any reed that doesn't sound has one of three problems:

• It's about to fail. Pluck it several times in succession to see whether it dives into its slot - that's a reed on the way out. if the pitch suddenly lowers, it's about to fail. It may even break off while you pluck it.
• There may be debris blocking the reed's free swing through the slot. Examine it carefully; use a magnifier and bright light if needed. If you see debris, slide it along the reed to the tip - NEVER yank on debris, especially fibers, as this may bend the reed up and out of shape.
• If no debris is visible, try pressing the tip of the reed ito the slot. If it scrapes and/or fails to emerge, it may be out of alignment. You may need to pivot it back into alignment, either by using a reed wrench at the base of the reed, or by wedging a thin, stiff piece of metal (such as a feeler gauge tongue) between the reed ad the slot to nudge it back into alignment. This can be fussy work, as it's easy to go too far (or nudge it in the wrong direction if you're not sure which way it needs to go).
• The reed may be in alignment and have no visible debris, in which case you should use an extremely thin piece of metal, such as the steel strips contained inside merchandise anti-theft tags, to swage the reed - that is to run the swage (thin piece of metal) up and down along the space between the edge of the reed and the slot to remove burrs or other material that may be impeding the reed's motion through the slot.

Blow reeds can be poked up throough the slot with something like an re-bent paper clip (but first smooth the sharp edges of the end of the clip to avoid scratching the reed). Poke the reed up through the slot, place a fingernail or other thin wedge under the reed tip, remove the reed lifter, then let the reed go to see what happens. When poking the reed up through the slot, be careful not to flex the reed so far that you change the gap. You can swage a blow reed without removing the reedplate, while nudging a reed back into aligment is more difficult.

What about removing the reedplates? First, the wood used for Wiener harps tends to be harder than the pearwood used for single-reed diatonics and 270-style chromatics, which can become brittle with age. However, you should be as careful as possible. Pry up  nailed-on reedplate by inserting a thin knife edge between the reedplate and comb. Get the sharp end of the blade as close as possible to the nails, then press the sharp edge UP so that you don't cut into the comb. Start with the narrow ends of the reedplate before raising the long back edge. Raise the nails just enough so that you can pull them out with pliers. This helps you to avoid damaging the comb or bending the reedplate or nails out of shape. Save the nails for later re-use.

With the reedplates removed, you may want to flat sand the comb. If you're concerned about moisture deforming the comb, keep it in a jar of rice or dessicating packets. (As the reedplates have reeds mounting on both sides, flat sanding a reedplate is not an option unless you first want to remove all the blow reeds from the inside of the reedplate.)

Back to playing the harp.

Two frustrating things about playing Wiener harps:

• You can use a lot of air feeding four holes instead of one. Making the harp more airtight by flat sanding the comb can help, but you can also focus on breathing into only a draw pair of holes (two-hole vertical stack) or into a blow pair. This cuts your air use in half, but requires more precision in aiming your embouchure. I have some exercises to help with that if you're interested.
• Because blow and draw notes are in side-by-side separate holes, you can accidentally combine, say, Blow 2 with Draw 1 instead of Draw 2. You have to work on finding the combinations you expect.

of course you can tongue block a double reed harp. All those comb partitions can be a bit abrasive, though. That said, some very sophisticated tongue blocking techniques have been used on these harps in various folk traditions. For instance: https://youtu.be/ILVpucC2BLw

Hope this helps a little.