I have a contrabass recorder. It looks like the larger one of these

It may look odd but it has an excellent tone. The keys are large wooden flaps which makes for an easy reach and the fingering is exactly the same as any F recorder. The basic design is based on an organ pipe.

I occasionally play it in pub sessions where it always attracts interest, though usually positive once they have heard it. It is an excellent instrument for playing a bass line, even though it is a little quiet.