In music, groove is the sense of an effect ("feel") of changing pattern in a propulsive rhythm or sense of "swing". In jazz, it can be felt as a quality of persistently repeated rhythmic units, created by the interaction of the music played by a band's rhythm section (e.g. drums, electric bass or double bass, guitar, and keyboards). Groove is a significant feature of popular music, and can be found in many genres, including salsa, rock, soul, funk, and fusion. From a broader ethnomusicological perspective, groove has been described as "an unspecifiable but ordered sense of something that is sustained in a distinctive, regular and attractive way, working to draw the listener in." Musicologists and other scholars have analyzed the concept of "groove" since around the 1990s. They have argued that a "groove" is an "understanding of rhythmic patterning" or "feel" and "an intuitive sense" of "a cycle in motion" that emerges from "carefully aligned concurrent rhythmic patterns" that stimulates dancing or foot-tapping on the part of listeners. The concept can be linked to the sorts of ostinatos that generally accompany fusions and dance musics of African derivation (e.g. African-American, Afro-Cuban, Afro-Brazilian, etc.). The term is often applied to musical performances that make one want to move or dance, and enjoyably "groove" (a word that also has sexual connotations). The expression "in the groove" (as in the jazz standard) was widely used from around 1936 to 1945, at the height of the swing era, to describe top-notch jazz performances. In the 1940s and 1950s, groove commonly came to denote musical "routine, preference, style, [or] source of pleasure." Description Musicians' perspectives Like the term "swing", which is used to describe a cohesive rhythmic "feel" in a jazz context, the concept of "groove" can be hard to define. Marc Sabatella's article Establishing The Groove argues that "groove is a completely subjective thing." He claims that "one person may think a given drummer has a great feel, while another person may think the same drummer sounds too stiff, and another may think he is too loose." Similarly, a bass educator states that while "groove is an elusive thing" it can be defined as "what makes the music breathe" and the "sense of motion in the context of a song". In a musical context, general dictionaries define a groove as "a pronounced, enjoyable rhythm" or the act of "creat[ing], danc[ing] to, or enjoy[ing] rhythmic