Whole note they may occasionally be put under a different line (or ledger line) in more complicated polyphonic passages, or when two instruments or vocalists are written on one staff and one is temporarily silent. The whole note and whole rest may also be used in music of free rhythm, such as Anglican chant, to denote a whole measure, irrespective of the time of that measure. The whole rest can be used this way in almost all or all forms of music. The symbol is first found in music notation from the late thirteenth century . The whole note derives from the
Value of time can be examined. For example, if a traveler has a choice between a coach which takes six hours and costs £10, or a train which takes four hours and costs £30, we can deduce that if the traveler chooses the train, their value of time is £10 per hour or more (because they are willing to spend "at least" £20 to save two hours' travel time). The difficulty in narrowing down the "actual" value of time from a pair of choices means that hypothetical situations are generally used (the stated preference technique) to deduce values of time. The value of