Ghost note (of Motown), Rocco Prestia (for Tower of Power), and Chuck Rainey (for Steely Dan, Aretha Franklin, and others) all include "tons of ghost notes done right" in their playing. In vocal music, especially in musical theater, a ghost note represents that the lyrics must be spoken rather than sung, retaining the marked rhythm but having indeterminate pitch. Notes with value less than a half note use an "X" instead of an oval as a note head. Occasionally a half note or whole note is represented with an open diamond note head, often representing a scream or grunt. As an extreme
Time value of money on time value, and provides a simple introduction before considering more complicated and less familiar situations. This exposition follows . The fundamental change that the differential equation perspective brings is that, rather than computing a "number" (the present value "now"), one computes a "function" (the present value now or at any point in "future"). This function may then be analyzed—how does its value change over time—or compared with other functions. Formally, the statement that "value decreases over time" is given by defining the linear differential operator formula_37 as: This states that values decreases (−) over time (∂) at the discount