A drum that does not have a skin tensioning mechanism.
This is the 'traditional' presentation of the instrument and skin tension is adjusted using moisture to lower pitch and heat to raise pitch.
This page refers to adjusting drums with natural animal hide heads.
Fixed plastic heads are non-tunable
A drum is 'in tune' when the tensions across the head are even. This is known as being in tune with itself and bears no direct relation to the pitch (high or low) of the drum. A drum may be in tune with itself at a high pitch or at a low pitch. The pitching of a bodhrán is generally a player's own subjective choice and you may choose to tune to a specific note to work with other instruments or just to a pleasant tone.
A 'non tunable' instrument will have a skin stretched over a frame in a fixed manner. There is no mechanical method of adjustment. This is standard on older and cheap or tourist quality instruments, it is relatively rare on a contemporary professional quality instrument. Fixed tuning is also seen in the form of a mylar (plastic) head on the bodhráns produced for a Middle Eastern Style of play.
- This tuning method involves using moisture to loosen an over-tight drum or using heat to evaporate moisture on a too-loose drum. It lacks subtlety but is effective.
- A plastic non-tunable head is non-tunable
- A plastic non-tunable head will eventuality drop in tone and become unplayable
- There are many theories about restoring these heads, I remain unconvinced
Tuning a non-tunable bodhrán
This sounds like an oxymoron, how can you tune something that is non-tunable? well, the answer is to learn to work with the natural qualities of the skin, adjustment is based primarily on heat and moisture.
There is little control available for fine adjustment of the tension on the drum and you will be looking for a general overall pleasant tonality. If you have specific tuning needs or requirements then I suggest that a non-tunable drum may not be for you.
Plastic-headed drums In the case of drums with heads made of mylar (plastic), the name 'non-tunable' is completely appropriate. These heads do not react to ambient level heat or any moisture. The application of heat (sometimes even direct very hot sunlight) will not tighten the head but will soften and deform it - be warned. They are non tunable and you need a new drum.
Too Tight Commonly a bodhrán will be found to be too tight, this is not just an 'exported' problem, here in Ireland we have that same problem too but not to the same extent as dry parts of the world where the issues are worse.
The only way to lower the pitch and reduce tension is to apply moisture to the skin in order that it softens and becomes more flexible. The moisture should be applied to the skin on the inside of the drum only.
Water only should be used - DO NOT USE BEER it will ruin your skin.
Moisture takes only a few minutes to have an effect and therefore should be applied sparingly if you intend to play the instrument in the immediate future. It is very easy to over-apply water which will leave you with a soggy skin and an unplayable drum (see too loose below) so do it in stages.
There are a number of recommended ways of applying water.
- Using a plant mister is the preferred method. Spray the entire inside of the drum with a light misting of water and use your hand to spread it around. It may take several applications to bring it down to achieve the desired tone depending on the original degree of tightness. You will find that the drum will tighten up with playing because of heat and friction and re-application should be carried out as necessary
- Using a cloth. Simply take a damp cloth (but not soaking) and rub it around the inside of the drum. The skin will absorb the water from a cloth as soon as they come in contact so rub lightly, quickly and cover as much of the drum's surface as you can in one go. It may take several dampenings of the cloth to achieve this but leave a couple of minutes between each application to give the drum a chance to settle at its new state. Re-application will be needed to counter the friction & heat from the hand during playing.
- Pour it in, slosh it about. This is not a recommended way of de-tuning the drum for a number of reasons. The water will tend to gather at the edges where the skin touches the shell giving uneven tensions. The wood may absorb the water and become swollen or misshapen. It is very easy to over-do it and you may end up with a floppy dead skin requiring remedial action (see below). You will have difficulties at a seishun in finding somewhere apart from the floor for pouring the excess water out into.
- DIY Humidifiers. A contributor to one of the bodhrán discussion fora whose name I forget, sorry, suggested that where a drum is always tight, it is worth carrying a humidifier to keep the air moist inside its case. His excellent suggestion was to use a film canister with a hole in top and bottom. Place something in the botton of the canister to provide a buffer, a washer was suggested and then drop in some damp sponge. The moisture in the sponge will be drawn into the air.
Clearly the bodhrán skin is a very sensitive item and you will find that a non-tunable bodhrán will require fairly constant attention. A skin that has been well played in will be less susceptible to ambient heat moisture and changes but will still suffer the same effects.
Too loose This is a common problem with bodhráns that have old skins, that have been stored in a damp atmosphere or that are being exposed to moisture laden air. Just as the process of loosening a skin uses the application of moisture, the opposite holds true for tightening the skin, it's all about taking the moisture out. The process is evaporation by heat and is generally slower than the process of de-tuning a tight drum
Hand heat The act of playing the bodhrán means that the left hand is almost always in contact with the skin. Given that the hand is at body temperature, the skin will absorb heat from the hand until they equalise. Furthermore the motion of the hand over the inside of the skin will cause friction which will generate even more heat. Both of these activities will remove moisture from the drum to affect the tension and pitch. In many cases this is the only action that is required for a non-tunable drum. If this is insufficient then you have to look at applying heat from another source.
Applying heat There are many ways of applying heat to the drum, any heat source that does not produce moisture will do and many inventive ways exist. The important thing to remember is that you want to heat the air around the drum rather than the skin itself (which will be heated by the air). Do not ever place your drum head directly against any heat source (e.g. radiator or blow heater) particularly when very damp, as you will destroy it.
When using any heat source, it is important to remember that you are dealing with natural skin. It will burn just as easily as your own skin but will not regenerate. The safest way of ensuring that you do not burn the skin is to keep your own hand between the drumskin and the heat source. If it's too hot for you, it's too hot for the drum.
When heating the skin, you can speed the process up slightly by heating both sides, turning the drum every couple of minutes. Heating the inside of the drum will create a chamber of warm air if the drum is held above the heat source.
The raise in pitch/tension will be slow initially but will speed up as the moisture reduces. Check the drum often once the process has started.
De-humidifiers. If you find that your drum is continually too low in pitch you may wish to add a few sachets of silica gel to your instrument case, this will absorb moisture in the air.
Summing up As you can see the tuning of a non-tunable drum is basically a balance between heat and moisture. The drum will always seek to equalise with the dominant ambient force, if you are playing in a desert then the drum will always want to become tighter and will need more constant work, if you are playing on a damp cold day then the drum will want to become floppy. There is a certain amount that can be done if the builder knows where the drum is to be played however that makes the instrument ambience-specific.
The worst possible combination of scenarios are humid, hot and moist, atmospheres, humidity kills bodhráns and you will find it very difficult to keep sufficient tension on the drum.
Not quite so bad are air conditioned atmospheres but they will remove moisture and you will be constantly misting to bring the pitch down.
Whatever your atmosphere, the adjustment of your drum is a continual necessity and you should become familiar with its reaction to where it is and reaction to your interaction with it. When you have this familiarity, you will know how to prepare and treat your drum so that you and those with whom you play are able to get the most enjoyment from it.