As with the tenor-recorder/English-flute, Woody, when one plays a tune on the chromatic baritone English concertina (which I still think has a nice homely timbre) they are playing the very tune/top-line melody on the score - which, if also a singer, they can, of course, readily match with their voice. I also like the Anglo, but it is not fully chromatic and, with it's push-pull system, is more likely to develop holes and the associated gushing sounds that slightly spoil the timbre.
more rubbish from WAV,the timbre of a concertina varies from instrument to instrument,to some extent it is dependent on the materials used,metal ends are brighter.however Ihave several different ebony ended concertinas and they all have a different timbre.
baritone concertinas do not always copy first treble,this is rubbish,I played in the New Mexborough English Concertina Quartet,and am very well acquainted with four part arrangements for concertina,they occassionally play the same notes as First treble,but a lot of the time play a chordal part.
Anglos dont develop holes because they are diatonic,concertinas develop holes because idiots play the bellows over their knees,thus wearing them out.
Wav you are out of your depth