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MMD > Archives > August 2005 > 2005.08.11 > 04Prev  Next

Boyd Pistonola & Terpretor Player Piano Action
By David Perry

-- non-subscriber, please reply to sender and MMD --

Greetings to the MMD fraternity.  With the MMD so obviously an American
forum, I am somewhat diffident about posting something relating
principally to the UK.  However, I am persuaded by colleagues to do so.

Back in 2000, MMD carried a brief but interesting exchange of messages
relating to a rather peculiar player action: the "Pistonola".  It may
be recalled that this was a unique all-metal action, developed in the
UK by H C Goldman and C F Webb in London before 1909, and represented
a fundamental re-engineering of the player mechanism -- abandoningleather, rubbercloth and wood in favour of brass and an alloy known
as "Mazak" -- and utilising the skills not of the organ-builder and
carpenter but those of an engineer.

The action was marketed for about 10 or so years in the UK, exclusively
(so far as we know) in player pianos made by Boyd Pianos of London,
until it was finally abandoned in favour of a more conventional player

The unique characteristic of the Pistonola action is that it employs
pistons rather than pneumatics, not only to generate the main vacuum
exhaust (from normal pedals), but also to operate the individual notes.
In addition, tiny pistons are also used as the driving valve mechanism
throughout the action.  If any further information is required about
this fascinating action, I suggest that reference is made to the MMD

It is almost folklore here in the UK that "Pistonolas never work".
And, I must say that, until recently, I believed this popular view.
Yet contemporary critical accounts of the mechanism hailed it almost
as the wonder of the age and "the player action of the future".  So,
it did seem that it worked very well at the time.

So why did the mechanism fail?  A problem has always been that few
pianos fitted with this particular action seemed still to exist.
Reference is always made to "the one that sold on e-Bay a few years
ago", but apart from that, nothing.

Always up for a challenge, a small group of members of the Player
Piano Group (UK) has been quietly working to find some answers.
We have so far found, and examined, here in the UK two players fitted
with the 'Pistonola' action and, surprisingly, four pianos fitted
with the 'Terpretor' action (which was an 'improved' version of the
Pistonola, slightly re-engineered and with additional 'bells and

(Note that 'Terpretor' is actually spelt like that, not 'Terpreter'
as one well known book on player-pianos would have you believe.)

We are in process of preparing precise drawings of all the primary
player components, together with a tubing diagram, for both the
Pistonola and the Terpretor.  We have already found that there are
important differences between all five pianos, indicating that the
mechanism was evolving even as it was being sold -- or perhaps that
there were enhanced versions that could be bought for a few pounds
more.  That said, however, it is clear that all the actions work on
the same basic principle, even if the actual mode of achieving the
final objective varies somewhat from instrument to instrument.

We are also in process of restoring a Pistonola and two Terpretors,
just to see if we can make them work as well as they apparently did
when new -- and in so doing, establish once-and-for-all the reasons
why these actions finally failed (and have gained such a bad reputation
over the years since).

All very interesting, but why bother the MMD?  For two reasons, actually.

Firstly, as you might expect, we would like to make contact with any
other owners of player pianos fitted with either the Pistonola or
Terpretor action, so that we can make further comparisons with those
instruments we have already been able to examine and thus check for
further variations.  Ideally the pianos would be located in the UK,
but I suppose it might be practical to exchange info with other owners
worldwide using photographs and the Internet.  It would be interesting
to know, for example, if any players with these mechanisms 'escaped'
from the UK and were sold abroad.

Secondly, we have recently been successful in sourcing here in the
UK compacted graphite of the correct density to enable us to machine
up both new motor pistons and also the smaller striker pistons.  (We
have found that the former are frequently damaged, being just too
accessible over the years to misguided intervention with oil(!) and
a sharp implement when the motor stopped working.)

And we are currently checking out a potential replacement for the fine
rubberised cotton cloth that was used in the valve mechanism.  So we
would like to hear from other Pistonola/Terpretor owners who would be
genuinely interested in restoring their player mechanisms and would
be willing to join with us in making viable a one-off order to the
manufacturers of these replacement materials.

I expect that this message will be prefaced prominently by the
organisers of MMD as being from a "non-subscriber" and I hope that
this will not put anyone off!  We are really quite genuine!

 [ I feel badly when I flag the author as "non-subscriber", but it's
 [ needed to remind our subscribers that simply clicking on "Reply to"
 [ sends the reply only to the MMD subscribers and not to the author
 [ who requested the information.
 [ MMDigest is transmitted daily to 1240 subscribers; at least 200 are
 [ known to reside outside USA, including 58 in UK, 33 in Australia
 [ and 20 in Canada.  -- Robbie

If there are any of you out there who share our fascination with this
amusing little cul-de-sac in the history of the British player-piano,
you are warmly invited to contact us at and to
share your knowledge and interest with us.  We shall be publishing news
of our progress in the Player Piano Group's Bulletin from time to time
and may, hopefully, prepare a small pamphlet on the Pistonola for wider
circulation, based on our experience.  Who knows -- one day we may even
see a restored Pistonola outshining the performance of more familiar
player actions!

Fraternally, and perhaps just a little eccentrically,
David Perry - "Pianolas at Guilden Morden"
Royston, Herts., UK

 [ David conducts the (London) Player Piano Group's roll auction,
 [ "Postbid Plus".
 [ MMD articles about the Boyd Pistonola are indexed at
 [ Several photos and diagrams with text are offered at
 [ and a unique home-built version is described at
 [ -- Robbie

(Message sent Thu 11 Aug 2005, 20:29:10 GMT, from time zone GMT+0100.)

Key Words in Subject:  Action, Boyd, Piano, Pistonola, Player, Terpretor

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