Musical Acoustics Paper on the Harp

The Harp is the oldest known stringed instrument, made up of a frame that surrounds multiple strings. The amount of strings depends on the size and type of harp, the concert harp typically has 47 strings which ranges 6 and a half octaves. The word harp comes from the Anglo-Saxon word meaning “to pluck”. Smaller instruments similar to the harp include the lyre, which has strings of the same length but of varying thickness and tension; the psaltery, which has a frame open only on one side; and the dulcimer, which is similar to the psaltery but which is played by striking the strings with a hammer rather than plucking them. The harp is thought to have origins in a hunters bow, in the sound it created when plucked. Because of this there is no true date of invention of the harp. There are cave paintings that depict a harp like instrument in France dated to 15,000 BC. The first types of harp were the bow harp, which has a single curved piece of wood attached to a resonating vessel, and the angle harp which is commonly called the open harp, which is made of 2 pieces of wood, one being hollow to resonate the sound, attached together at an angle with the strings strung between them.

The harp was developed separately in different parts of the world and during different time periods but all seemingly producing similar types harps. In ancient egypt there are many harps depicted in Pharaohs tombs around 5000 years ago the majority of these being bow harps up to 2 metres with 19 strings.

Vertical harps known as lyre harps were created in ancient Greece and coincided with the creation of the mathematical musical scale where Pythagoras discovered numerical ratios corresponding to intervals of the musical scale. During the Roman times the use of the harp and musical instruments in general declined and did not reappear for many years.

The triangle harp seems to have been developed in Europe and incorporated a vertical pillar to close the frame, the effects of this mean that it allowed the harp maker to increase string tension without distorting the instrument which also made the harp easier to tune as changing the tension of one string no longer affected the tension of all the other strings. The frame of the triangle harp is normally made of wood with the soundboard being a different type to the main body. Common woods used are spruce, beech, and maple with maple being the most common. The strings are stretched between the soundboard, which is the slightly slanted and uncurved arm of the entire triangular frame, and the curved, often elaborately carved, top. The strings are often made of nylon or wire. The main modern types of harp are the pedal harp and the lever harp.

Pedal harps are usually used as concert harps and usually have a number of pedals at the base which are used for changing notes and for switching keys. These typically have between 41 and 47 strings. Lever harps which are commonly known as celtic harps or folk harps, are floor harps and have no pedals. These have between 20 to 40 strings. The pedal harp has been improved to include a double action so that the note they are attached to sharpens a semitone on the first depression and a further semitone on the second depression. The pedals were originally designed with hooks that attached on the end of the strings and pulled down tightening the string.

The hooks were then updated to crochets, which were right-angled rather than the u-shape of the hooks, then to bequilles, which are sets of two small levers in which each string wrapped through; when one of the pedals were depressed, one lever would turn clockwise and the other counter-clockwise, providing a firmer grip. This was a better system but it tended to break and prone to a buzzing sound being produced. This was then overcome by the introduction of the disk system which is made up of two brass prongs (or forks) extended from a disc that a string passed through before attaching to the tuning peg. When the corresponding pedal was depressed, the discs turned and the strings sharpened a semitone, held firmly against the prong. The pillar contains the rods that operate the mechanism of the pedals.

Lever harps, however, do not have pedals or rods, and the pillar’s only purpose in these instruments is to hold up the neck against the large amount of strain of the strings. Lever harps use a shortening lever on the neck next to each individual string which is to be activated (i.e., turned) manually to shorten the string and raise the tone a half step. A string tuned to natural may be played in sharp, but not flat. A string tuned to flat may be played in natural, but not sharp.

How it is Made

The harp is made of 5 main parts these parts are the body, the neck, the pillar, the sound board and the strings. The strings are connected between the neck and the body. The neck, where the top of the string is connected, contains the tuning pegs which alter the note of the string by changing the tension. The holes in which contain the tuning pegs are drilled at specific intervals so each string is the same distance apart and that the length the string will be the correct lenghth. when connected to the sound board. The bottom of the strings are connected to the soundboard, they are fed through small holes and are then tied in a knot inside the soundboard to keep them secure. The soundboard is the upward facing surface of the body. The body is hollow and reinforced with internal ribs, when a string is plucked the body resonates and sound is projected towards the players through holes in the body, which are mainly used as a access to the strings but have the added use for projecting sound to the performer, and more powerfully outwards towards the audience through the soundboard which is flexible and kept taut.

The pillar of the harp is mainly to support the neck by connecting it to the body to allow for higher tension strings and more strings, it is also used in pedal harps to contain the rods that control the mechanism used to change the tension of strings through the performance. White maple is the best wood for these three sides because it is strong enough to withstand the stress of the strings. The soundboard is usually made of spruce. Spruce is used because it is light, strong, pliable, and evenly-grained, enabling it to respond uniformly to the vibrations of the strings to produce a rich, clear sound. The middle of the soundboard, known as the centerstrip, is attached to the base of the strings and is usually made of beech. Beech is used because it is tough enough to bear the tension of the strings.

A modern concert harp stands about 70-75 in (1.8-1.9 m) high, is about 40 in (1 m) wide, weighs about 70-90 lb (32-41 kg), and has 47 strings, ranging in size from a few inches to several feet in length. Some harps were double strung which added a second row of strings which were played by passing a finger between two strings a harpist could reach the corresponding chromatic note in the other row. This led to the invention of the triple-strung harp which was designed to be played with two hands, The triple-strung harp had three rows of strings, the two outer rows were tuned to the same diatonic scale while the inner row was tuned to the outer rows’ chromatic semitones. This had the benefit of songs with rapidly repeated notes being more easily played and playing the same note on either side amplified that note by increasing the resonance in the body.

There is no set mic’ing technique for a classical harp as mic’ing the strings will lose the body and warmth of the harp, and solely mic’ing the sound board will lose the attack from the strings so a combination of stereo pairs, close mic’ing and ambient mic’ing is used to achieve an accurate representation of a harp. Experimentation with multiple set-ups is the standard method at recording a harp and choosing the preferred pairing, an example of this is shown (Microphones and Recording, 2008) using 4 stereo pairs in various positions around the harp. In this example the 4 pairs used are; a cardioid condenser pair in ORTF formation on one side of the harp, about 3 feet away.

A cardioid condenser pair in coincidence formation, on the same side a few feet from the harp. A pair of ribbon microphones positioned on the lower half of the harp close to the sound box on either side of the harp. A pair of omni directional condenser microphones above the harp on either side. The preferred pair in this instance was the cardiod pair in ORTF formation described as being bright with plenty of detail. In some instances some pairs can be mixed together to produce a well-rounded replication of the harp but in this case the pairs were placed in many locations introducing phase issues to the mix.

Alison Vardy (http://www.alisonvardy.com) has categorised different techniques used to produce a replication for certain genres these methods are; Classical, True Classical, Pop and meditative. The classical method uses three microphones a pair on either side panned left and right positioned near the players respective hand and a mono large omni-directional microphone infront and above the harp to capture the room ambience. The true classical method uses a LR pair infront of the harp close to the body with a 3rd further back in the middle to give the mix more space.

The pop method is described as providing a strong chiming to the mix with one microphone above the players hand capturing the action from the strings, panned partially to one side and one at the base of the harp to capture the bass of the harp, panned partially to the opposite side with a mono microphone out front to capture the room sound. The fourth method described as meditative uses a stereo pair aimed towards the pillar of the harp at waist height with a third microphone above the hand centred to capture the action of the strings positioned in the centre of the mix.

http://en.wikipedia.org/wiki/Harp

http://www.alisonvardy.com/harp-info/medieval-harp-history.htm

http://www.enotes.com/harp-66393-reference/harp

http://us.harp.com/history-of-the-harp.htm

Microphones and Recording 2008 http://www.recording-microphones.co.uk/recording-harp.shtml