Helen, you said:"I do "fan the bellows" a lot of the time as well - though without the aid of a strap but I can see that it might assist if you have a lot of air in the concertina. Mine are standard 6-fold Lachenal trebles and I like them a bit leaky because then you have to move them faster!"

- I have to repeat that you don't need a lot of air/large instrument or long bellows to gain from "fanning" or using the strap.On the contrary even ! - particularly with the strap fanning makes "pumping" (that is what you are up to in real - sound may be looked upon as a side effect...) so much more efficient that it mostly is a musical advantage as well.There are very few long phrases that may demand the full extension of any bellows.Precisely as you say for yourself - the method reversing the bellows according to muscical rhythm and articulation is of greater importance than bellows capacity. BUT
I have to object concerning fancying the leaks! I know exactly what you mean: I once had a real big piano accordion that leaked and it seemed very comfortably 'easy' to play initially but after tightening the bellows it was not difficult to realize that bellows should be dead tight if possible!You can play exactly as rhythmical , just with smaller movements! Check it! Of course - if you play polyphonic hymns or song accompaniment on a little treble you do get out of air...
The straps if used should be attached so you just snip them on and off

Dick (Miles),
- First, I sympathize will all you are saying (almost:-). Just adding a little:

"no one correct way of using the bellows"
- I fully agree! Everything has to be carefully choosen according to circumstantial needs.What Iam advocating for is the primary approach that this choice better be based as long as possible upon fundamental anatomical and physcial conditions, and these are not changeable!With that as the starting point you can(or have to) compromise in various ways depending on the specific music and situation.

"Baritone concertinas were designed to play parts and only play melody occasionally,Ispeak from experience,I played in the NMEC,1985"
- Hm..I don't fully agree! a) They can be suitable of course for playing 'baritone'range solo/melody. Perfect for cello or guitar solos for example. b) For accompaniment they can be very suitable also with chordal/polyphonic styles BUT it may be bloody tricky to avoid getting a muddled mess of it all. c) For polyphonic hymn (solo) playing they are outstanding among concertina models. d) "designed" - well that differs a lot does it not! They may be so very different in sound , response, distinction, tonal balance.(Long reed single action old ones entirely different from modern short reed compromise models etc) e) Baritone trebles - which are my favourites - may have additional characteristics while still being possible to play like any other baritone or almost any treble(!). f)comparing tone in the same octave I think you often notice a warmer, mellower tone from the baritone compared to the treble and that may enrich the expression many times, comparable to playing the same violin part on a viola or a cello instead.

-Concerning legato/staccatto never take my own playing as any kind of musical example! I do play more legato than I might prefer but that is due to physical handicaps. Something I would like to emphasize in this issue is that many (most..) concertina players, compared to at least more advanced accordion players, seemingly are not familiar with fundamentals on basic articulation..i.e they may 'know' in practise but don't understand what they are actually doing physically.
"Staccatto" for instance is not only *that*. It may be performed by either a)'finger articulation' or b)'bellows articulation' and there is great difference. a) means that the bellows are activated first and the sound is initiated when the button is pressed b) means that the button is activated/pressed first and the sound is initiated when the bellows are moved. (Something for another topic maybe...?)

Cheers
Goran