There have been a couple of discussions at www.concertina.net recently that might need to be commented upon since some misunderstandings come up in the messages involved.

The particular threads are these:
http://www.concertina.net/forums/index.php?showtopic=18031
and
http://www.concertina.net/forums/index.php?s=40c90973f7d6057c9108645057f4fd1a&showtopic=14746

Comments:

1. Control/efficiency of the bellows is better on pull than on push. This is a mechanical fact with all squeezeboxes.

Firstly, on pull the bellows stabilizes itself, no extra muscular effort is needed to stabilize the system and muscular resources may be recruited for other duties

Secondly, on pull the pad valves seal better while on push particularly on concertina models with varying pad diameter the low pads even tend to leak audibly with forcible playing.

Individual habits may mislead players to believe otherwise. In general the above means that mostly the strong musical beats ought to be on pull, not on push - analogous with downbow and upbow on violine playing.

2. Straight or fanning way of bellowsing.

a) Straight bellowsing traditionally has been recommended in many tutors since long time. The origin of the advice likely is unknown but my guess is that *makers* came up with it with the intention that bellows might be less subject to wear and tear. The playing no question gains from fanning in most situations, but not all.

The stability may be very much improved by fanning and particularly when using a "cross the bellows strap" which I have been advocating for since long ( and "Ratface" Danny Chapman who is mentioned in one of the threads has adopted )

3. WHEN using the fanning method there are two main situations to consider:
a) when playing seated the LOWER part of the bellows should be kept closed
b) when playing standing (and/or using a supporting neck/shoulder strap) the OUTER part of the bellows should be kept closed.
This is the cause of the referred confusion in the discussion which was related to the advice by Wim Wakker who plays standing and uses a neckstrap also.