which gives it a rustic sound, since this wood possesses differences in density that produce a different timbre than normal xylophones. Glass marimba – the keys are made of glass, which produce notes of greater resonance than those made of wood. String instruments with bows Played by Marco Antônio Guimarães in recordings, they are, in general, inspired by the cello or the viol. Iarra - A type of cello, with two sets of strings that can be pressed simultaneously with the left hand. A bow is used to play the string. Chori Smetano - an instrument created by Walter Smetak. Basically it is a string instrument with a sound box for a head. According to its inventor, this instrument can simultaneously create opposing feelings, such as crying and laughing. This is the origin of the name "cho-ri" ("choro"="crying", "riso"="laughing" in Portuguese). Guimarães built his chori with the arm and bow length of the cello, so that any cellist can play it. Torre (Tower) - A large PVC tube with a double bass ridge at one end and a handle at the other. Strings are stretched along the sides of the tube. Two musicians are needed to play it. One turns the tube on its axis with the handle. The other uses a bow composed of two rods, and a horsehair viola bow to rub the strings. Since the bow can play several strings at once, it can play chords. Changing the velocity and quantity of notes with the bow gives rise to harmonic variations. It is one of the most astonishing instruments to see in live performances because of the rich harmonics produced and the unusual method of playing. It is normally used as a harmonic base. Drums The membranophones are also an important part of Uakti's sound, principally the trilobyte, formed out of 10 tuned PVC tubes arranged on a frame, with drum skins over the top ends. Two musicians position themselves facing each other, holding the instrument between them, and use their fingers, drum sticks, or the palms of their hands to strike the skins, producing quite rapid melodies. Traditional instruments The group also uses some traditional instruments. They use various types of drums such as atabaques and floor toms, and also tablas, traditional (Asian) Indian drums. Occasionally they use string instruments such as the violin or piano, though they usually play them using drum sticks and other