During the 1800s, influenced by the musical trends of the Romantic music era, innovations such as the cast iron frame (which allowed much greater string tensions) and aliquot stringing gave grand pianos a more powerful sound, with a longer sustain and richer tone. In the nineteenth century, a family’s piano played the same role that a radio or phonograph played in the twentieth century; when a nineteenth-century family wanted to hear a newly published musical piece or symphony, they could hear it by having a family member play it on the piano. During the nineteenth century, music publishers produced many musical works in arrangements for piano, so that music lovers could play and hear the popular pieces of the day in their home. The piano is widely employed in classical, jazz, traditional and popular music for solo and ensemble performances, accompaniment, and for composing, songwriting and rehearsals. Although the piano is very heavy and thus not portable and is expensive (in comparison with other widely used accompaniment instruments, such as the acoustic guitar), its musical versatility (i.e., its wide pitch range, ability to play chords with up to 10 notes, louder or softer notes and two or more independent musical lines at the same time), the large number of musicians and amateurs trained in playing it, and its wide availability in performance venues, schools and rehearsal spaces have made it one of the Western world’s most familiar musical instruments. With technological advances, amplified electric pianos (1929), electronic pianos (1970s), and digital pianos (1980s) have also been developed. The electric piano became a popular instrument in the 1960s and 1970s genres of jazz fusion, funk music and rock music.