In music production, the recording studio is often treated as a musical instrument when it plays a significant role in the composition of music. Sometimes called "playing the studio", the approach is typically embodied by artists or producers who favor the creative use of studio technology in record production, as opposed to simply documenting live performances in studio. Techniques include the incorporation of non-musical sounds, overdubbing, tape edits, sound synthesis, audio signal processing, and combining segmented performances (takes) into a unified whole. Composers have exploited the potential of multitrack recording from the time the technology was first introduced. Before the late 1940s, musical recordings were typically created with the idea of presenting a faithful rendition of a real-life performance. Following the advent of three-track tape recorders in the mid-1950s, recording spaces became more accustomed for in-studio composition. By the late 1960s, in-studio composition had become standard practice, and has remained as such into the 21st century. Despite the widespread changes that have led to more compact recording set-ups, individual components such as digital audio workstations (DAW) are still colloquially referred to as "the studio". "Playing the studio" is equivalent to 'in-studio composition', meaning writing and production occur concurrently. Definitions of the specific criterion of a "musical instrument" vary, and it is unclear whether the "studio as instrument" concept extends to using multi-track recording simply to facilitate the basic music writing process. According to academic Adam Bell, some proposed definitions may be consistent with music produced in a recording studio, but not with music that relies heavily on digital audio workstations (DAW). Various music educators alluded to "using the studio as a musical instrument" in books published as early as the late 1960s. Rock historian Doyle Greene defines "studio as compositional tool" as a process in which music is produced around studio constructions rather than the more traditional method of capturing a live performance as is.