Electrical recording was common by the early 1930s, and mastering lathes were electrically powered, but master recordings still had to be cut into a disc, by now a lacquer, also known as an Acetate disc. In line with the prevailing musical trends, studios in this period were primarily designed for the live recording of symphony orchestras and other large instrumental ensembles. Engineers soon found that large, reverberant spaces like concert halls created a vibrant acoustic signature as the natural reverb enhanced the sound of the recording. In this period large, acoustically "live" halls were favored, rather than the acoustically "dead" booths and studio rooms that became common after the 1960s. Because of the limits of the recording technology, which did not allow for multitrack recording techniques, studios of the mid-20th century were designed around the concept of grouping musicians (e.g., the rhythm section or a horn section) and singers (e.g., a group of backup singers), rather than separating them, and placing the performers and the microphones strategically to capture the complex acoustic and harmonic interplay that emerged during the performance. In the 2000s, modern sound stages still sometimes use this approach for large film scoring projects that use large orchestras.