Piano Tuner in Inverclyde, Renfrewshire, Glasgow, the west of Scotland and beyond.
Clementi Sonata in Bb 1st Mvt.mp3
The piano above has what is often called the Birdcage action. The correct name for this is the Overdamper action (also sometimes called an overdamped action). It's easy to see how the name "birdcage" was derived from the vertical damper wires at the front of the action, which resemble the regularly-spaced bars of a metal birdcage.
Here is another photo of the same Birdcage action:
Another overdamper action:
In Overdamper actions the felt pads, or dampers, which stop the notes from sounding when you let the keys up, are situated above the level of the hammers, nearer to the ends of the strings.
All modern upright piano actions are of the Underdamper type, with dampers situated below the hammers, further down the strings.
The photo below shows an Overdamper action from the hammer side, with the dampers above the line of hammers. (Dampers do not extend into the high treble on any piano as the tones are of short duration there anyway).
Overdamper actions were popular, especially in budget-level pianos, around the end of the 19th century. They were often fitted to "straight strung" (also called parallel strung) pianos, where the bass strings do not run across diagonally over the treble strings.
Here is an illustration from a 1920s Catalogue of the Sames Piano Company. This is the cheapest model in the catalogue, straight strung and with Overdamper action:
Below is a line drawing of the overdamper mechanism for a single note. It is shown without the rest of the action. The hammer (not shown) which strikes the string, is situated just below the level of the damper.
The line drawing below shows a modern upright action, with the damper below the level of the hammer. In that position it works more efficiently to stop the string from sounding. It is worked by a spring, which pushes the damper felt against the string. In the overdamper, only gravity keeps the damper against the string.
Birdcage actions were less complex to manufacture, and tended to be fitted to the cheaper, straight-strung pianos.
Towards the end of the 1800s a thriving "cottage industry" of small piano workshops developed in England, making cheap and cheerful instruments to suit the budget of the lower middle classes, who by that time had the means and the desire to own a parlour piano. Scores of thousands of entry-level pianos were churned out by such workshops, made down to an affordable price.
(There was a design of upright piano at this time called the Cottage Piano - see the bottom of the Technical Info 1 page. That's not what I mean here by "cottage industry"; I am using that term in its general sense).
In that era, beautiful hardwood veneers and the skilled labour to work with them were cheap. A result of this was that many of these late 1800s Birdcage pianos looked much better than they actually were. Look at the inside of the lid of this small 1800s Birdcage piano, for example:
Isn't that exquisite? Even on the inside of the lid, which would seldom be seen.
Here is the whole piano. After 130 years the casework can be expected to look a little tired, but even so, you can see that it was pretty:
As time went on the finish became less ornate. Below, you can see a photo of one of the later Birdcage pianos, typical of the size and style that was being produced in the 1930s.
Wth the top and bottom doors and the action removed, you can see the parallel stringing, sometimes called "straight-strung"
A similar example is shown below (photographs of these pianos by gracious permission of the owners).
With the top panel off the birdcage action can be seen:
This piano illustrates the phenomenon of "badging", which has always happened in the piano manufacturing industry, and still does. The name on the fall (keyboard lid) is not necessarily that of the factory which made the piano. This piano said Crane & Sons, an old English make, and the nameplate inside bears the Crane name:
The letter K in front of the serial number however shows that the piano was made in the Kemble factory:
This serial number dates the year of manufacture to 1941, and Bill Kibby of www.pianogen.org confirms that Kemble made pianos for Crane at that time.
Here is a close view of the little motif on the top panel, which is rather Art Deco in style. You may have noticed that the other piano of this type above, also had such a motif in the centre.
Although by the late 1930s, straight strung overdamper pianos were apparently being phased out in English manufacturing, Bill Kibby of pianogen has pointed out out that they didn't entirely cease production until later. The English maker Berry produced overdamper pianos into the 1950s, with the last of them going out in 1954. It seems likely that these were made using pre-war leftover stocks of these actions. Piano actions are made by separate specialist companies, and Herrburger Brooks were the main UK action maker.
Kemble, incidentally, were the last English piano manufacturer. They ceased production in October 2009, effectively ending 200 years of English piano manufacturing (there is still some craftsman piano building going on, but not on a factory scale).
Here is another late 1930s birdcage piano. As you see, it looks very similar to the two above:
Like the piano above it, this one too has the Crane name on it.
And like the Crane above, a look inside quickly reveals a Kemble serial number:
However, unlike the two Kemble pianos in the pictures above, this one doesn't have an Art Deco motif on the top door, and, ta-dahhh! it is an OVERSTRUNG birdcage.
Here it is with the action out. (Again, photos thanks to gracious permission of the owner).
And just to show that Kemble did sometimes use their own name on birdcage pianos, here's another little 1941 upright in the same style as the badged Crane, but bearing Kemble's own name:
The internal nameplate is very much in the style of the Crane & Sons model shown earlier on this page:
And here is the serial number (sorry about the quality of these photos, taken with my phone:
This is another English overstung birdcage, from a slightly earlier period than the Kemble models above, and a bigger, heavier instrument:
The photo below shows a really old birdcage piano where the damper rail partly obscures the bottom row of tuning pins. This piano can never have been properly tuned in its life, until I filed grooves in the damper rail to let the tuning lever get access. As it was, you had to use the tuning lever to lever the rail down while simultaneously tuning and "setting" the pins; an impossible task.
An infuriating aspect of many of the smaller overdamper pianos is that part of the bottom row of tuning pins doesn't quite clear the top of the overdamper rail and this makes it very difficult to seat the tuning lever properly on those tuning pins. There is really no excuse for this; it's just bad design, with only costcutting having prevented a solution.
German Birdcage Pianos
Birdcage pianos were also made in Germany. There, it was less of a bargain-basement thing: Bluthner notably made some huge and powerful pianos with Birdcage actions - there used to be three of them in my immediate area. Ibach were another German maker who had Birdcage actions in some fine pianos.
However, the German makers did not persevere with that type of action as long as was the case in the UK. They seem to have dropped those designs some time around the First World War. German-made Birdcage pianos are also more likely to be overstrung rather than straight-strung.
Birdcage actions do not "damp" the strings (stop them from sounding after you take your fingers off the keys) quite as effectively as underdamper actions, partly because the dampers are close to the ends of the strings where there is less string movement.
Here is a Youtube clip of one of the fine old Bluthner overdamper pianos (I can't bring myself to call such a piano a birdcage piano) being played, having been restored by its owner (I think it is being played by a meechanical player device):
I came across this very unusual German piano with both underdampers and a half-set of overdampers:
This unusual piano with its half-set of additional overdampers makes it easy to see how the overdamper mechanism works (I should have dusted the hammer rail before taking the photo!):
They were certainly determined that the bass strings of that piano would damp! That's an awful lot of damper felt, both above and below the hammers! (The top rail isn't really curved, it's an artefact of the wide angle of the camera lens).
Spring & Loop Birdcage Action
An early variant of the Birdcage action was the Sprting & Loop type. The top two photographs on this page show an Overdamper action of the Spring & Loop type. These actions were commonly used in the cheaper and earlier "cottage industry" pianos. Later Birdcage actions had Bridle Tapes, more closely resembling modern Underdamper actions, and worked better. The geometry of the Spring & Loop action was inferior, and in my experience, they never feel responsive, even taking into account their age.
The line drawing below shows a Spring & Loop mechanism for one note. It is shown without the overdamper, so you have to imagine the overdamper drawing above, in place here, with the damper above the hammer.
Modernised Birdcage Pianos
In Britain in the 1950s a fashion developed, for "modernising" the casework of older pianos, to make them look more contemporary. Ornate front panels were replaced with plain fronts and no candle sconces. Straight legs were replaced with curved. Top lids were shortened so that they did not overhang, and rounded corner mouldings fitted.
The following photos show a typical example:
The first two birdcage (or overdamper) action photos, at the top of this page, are of the Spring & Loop type action. Later overdamper actions were of the Tape Check type. The Tape Check, or Bridle Tape, is still what is used in modern underdamper actions to tie action parts together and assist hammer rebound. The third and fourth photos on this page are of a Tape Check overdamper action, as is the photo below.
You can see that the top panel does not quite match the keyboard lid (called the Fall).
The top panel has been replaced with a plainer look, lacking mouldings and candle sconces. The finish on the Fall is original.
Typically, such "modernising" involved shortening the top lid, which would originally overhang the top of the piano and have a wooden moulding round it (like the Sames model in the catalogue above). The sides of the modernised piano would then have a rounded moulding fitted, as below:
These curved legs are also typical of such refurbishments:
All of such renovations were purely cosmetic. They did nothing to improve the operation of the piano as a musical instrument, or to deal with fifty or sixty years of wear to the action parts. But it did make the piano look younger.
One client was very surprised when all this was explained to her. She insisted that the piano had been sold to her parents as brand new in 1957, but it was quite clear that it was a "modernised" piano. A 1918 date stamped on the piano's birdcage action helped to convince her.
What is the upshot of all this, as far as buying or owning a Birdcage piano is concerned? Broadly, the advice must be: Don't buy one, and if you own one, don't expect that it can be improved.
The high-quality German Birdcage pianos are now too old to be candidates for major improvement. The later UK Birdcage pianos, from the mid 1930s may still be decently playble, but they were of budget quality, and not really worth any great expenditure.
Worst of all are the late 19th century English cottage-industry Birdcage pianos, especially with the unresponsive Spring & Loop action. They were cheap to begin with, and are now around 130 years old. Action parts along with other parts of the piano do become fragile with age, and there is simply no scope to make such old Birdcage actions serviceable.
The line drawings on this page are taken from Piano Action Repairs & Maintenance by K.T. Kennedy, Kay & Ward, London 1979, now out of print.