I have an instrument called a gemshorn which is a recreation of an old European one made from the horn of the gesmbok of the Alps. Since gemsboks are now quite rare, my gemshorn is made from the horn of a Texas longhorn.The gemshorn is basically a curved section of horn, hollowed out and with finger holes drilled in it. It has a sweet tone and a range of an octave plus one note. There are makers selling them in horn and in plastic. Both the horn and the plastic have a nice feel to them. They are fingered like recorders, but obviously don't have as big a range.
I played my gemshorn in a concert (no sound system)in a chruch, and people tell me it carried well. Since I was fighting off a viola da gamba, that's impressive.
I suppose you could find them by searching for gemshorn on the net, or you could go to the Kelishek site. (That's where mine came from.)