The image indeed seems to be reversed, but I see no stud in either ear, just wisps of hair.

The Dodsworth Saxhorn Band often plays at events at Greenfield Village in Dearborn, MI. Their site has samples of their music on the CD page.

The instrument is a saxhorn, designed by Adolphe Sax of saxophone fame. They were quite popular with Civil War bands. Wikipedia has all the details and a couple of good photos.

It's an over-the-shoulder saxhorn. The saxhorns are a class of brass instruments with a conical bore and a cup mouthpiece. They are generally claimed to have been invented by Adolphe Sax, who also invented the saxophone. The flugelhorn and modern cornets and upright tubas are all saxhorns.

I see it says saxhorn in the caption - I must have misread it as I am a saxophone player. Please see attached a picture of some 160 year old over the shoulder horns. Horns from the John Phillip Sousa Museum.

I believe this is indeed a Saxhorn (a different beast from a Saxophone though also invented/patented by Adolphe Sax).

That is an over the shoulder horn. Saxophones did exist then but they were a reed instrument - not a brass instrument. My wife plays a horn such as this for special events via the John Phillip Sousa Museum where they have a collection of these instruments from the 1850's and 1860's. They were played at the head of a marching column with the bell aimed over the shoulder back to the soldiers behind. There are a range of instrument sizes (bass, tenor, etc) so there might be 4 or 5 horns and a drum at the head of a column providing music to march to. Once in camp they musicians might play for the camp at night and even compete with enemy musicians across the lines for playing best musical selections.

in no small part enhanced by the removal of an oval framing matte that must have been in place for quite some time.

Far more than the clothes, the expressions we find in the old photos speak volumes about the differences in mindset between then and now. Of course, sitting rigid for several minutes has something to do with it, but even so it seems a serious demeanor was deemed to have greater value then than now.

They're always ahead of their times. Our saxhorn wielding warrior seems to have a diamond stud in his right earlobe. Of course I understand that it is really his left ear because of the mirror image nature of the tintype.