Perhaps I am misreading this page but I lived in Tolagnaro for 14 months recently and the only instrument you see there (and I travelled quite extensively to the surrounding hamlets) is the guitar-like 'mandolina'. It was abundant and I don't see this reflected in the distrubtion maps? This was both in the town centre in people's homes and in hamlets for celebrations.
I saw occasional Valiha's in tourist shops and once or twice saw the musical bow played in the traditional ceremonies by neighbouring Tandroey people, but never in Tolagnaro by Antonosy people.
