Music is composed and performed for many purposes, ranging from aesthetic pleasure, religious or ceremonial purposes, or as an entertainment product for the marketplace. When music was only available through sheet music scores, such as during the Classical and Romantic eras, music lovers would buy the sheet music of their favourite pieces and songs so that they could perform them at home on the piano. With the advent of the phonograph, records of popular songs, rather than sheet music became the dominant way that music lovers would enjoy their favourite songs. With the advent of home tape recorders in the 1980s and digital music in the 1990s, music lovers could make tapes or playlists of their favourite songs and take them with them on a portable cassette player or MP3 player. Some music lovers create mix tapes of their favourite songs, which serve as a "self-portrait, a gesture of friendship, prescription for an ideal party... [and] an environment consisting solely of what is most ardently loved". Amateur musicians can compose or perform music for their own pleasure, and derive their income elsewhere. Professional musicians are employed by a range of institutions and organisations, including armed forces (in marching bands, concert bands and popular music groups), churches and synagogues, symphony orchestras, broadcasting or film production companies, and music schools. Professional musicians sometimes work as freelancers or session musicians, seeking contracts and engagements in a variety of settings. There are often many links between amateur and professional musicians. Beginning amateur musicians take lessons with professional musicians. In community settings, advanced amateur musicians perform with professional musicians in a variety of ensembles such as community concert bands and community orchestras.