Throughout the Middle Ages until the 15th century, the harp played a very important role in music, as it served as accompaniment. In Ireland, it became a national symbol. With the 16th century, it was replaced in accompaniment by the lyre and made its way to royal courts as a solo instrument.
The construction of the harp has always been different, mainly depending on the place where it was made. For example, the Irish harp was built from a single block of spruce, oak, or willow wood, had a very curved shape, and had 28 metal strings. It was held on the hips and rested on the left arm. On the other hand, the Celtic harp has 32 or 34 nylon strings tuned diatonically, which can be retuned by a semitone.
The medieval harp was diatonic, while the modern one was supposed to be chromatic, which went hand in hand with the developing Western music. In the 16th century, a harp with two rows was created, in the 17th century a third row was added, where the strings in the first and third rows were tuned by whole tones, and in the second row by semitones. In the mid-17th century, a mechanism was created that allowed the strings to be tensioned and thus raised the sounds by a semitone. However, it was only at the end of the 17th century that a harp with 7 pedals corresponding to the 7 degrees of the musical scale was created, on which Mozart himself wrote a concerto for harp, flute, and orchestra (1778). The harp in its modern version was designed by S. Erard in 1811. It has 47 strings and 7 pedals with a mechanism called double action. It is played by plucking the strings from both sides.
It was introduced to the orchestra by Monteverdi, and gained immense fame since the Baroque era, thanks to composers such as Berlioz, and later Fauré, Debussy, and Ravel. In orchestras, you can hear 1-2 harps, which are often used to mimic various sounds: water, wind, windmills, although there are also many works in which the harp does not appear.
BAROQUE
Joseph Haydn Concerto for Harp and Orchestra in B-flat Major - A. Andruschenko, A. Beryn. and Internationale Simphoniker Deutschland,
CLASSICISM
Wolfgang Amadeus Mozart Concerto for Harp, Flute, and Orchestra - Freiburger Barockorchester, Gottfried von der Goltz