One group of pitched and nonpercussion instruments were recognized as string instruments, for their construction and and usage of tension and strings or wires to produce tones. Harps were a type of string instrument used then that has not changed much between then and modern day, consisting of plucked strings, each individually tuned. The large harp and small harp were known as the sambuca and trigonum respectively. The lyre, also unchanging, was similarly built and had been used alongside the recitation of poetry. Another instrument, the kithara, was the predecessor to a modern guitar, consisting of a trapezoidal box with a hollow body and an acoustic sound hole, along with tuning knobs and mechanisms that could change pitch and keep it stable. The lute, also related to the guitar, was even more similar to its successor with a long neck and hollow body. It never achieved the popularity of the other instruments due to its relative complexity and lack of portability.