Rhythm in nor­mal mu­si­cal ex­peri­ence, be it for aes­thetic en­joy­ment or with an edu­ca­tional and thera­peu­tic pur­pose, as­sumes there are struc­tures in hu­mans which fol­low mu­si­cal con­for­mi­ties to a natu­ral law.
This is not only true for the im­me­di­ate re­ceiv­ing or­gan of hear­ing, for which e.g. in the form of a snail cor­re­spond­ing laws of for­ma­tion are known (cf. HAASE 1976), but it must ap­ply to the whole or­gan­ism; for the whole of a hu­man be­ing par­tici­pates as a mov­ing or­gan­ism, as a sen­sory or­gan­ism and as an in­tel­lec­tual or­gan­ism in ex­peri­enc­ing mu­sic.

Mu­sic and mu­si­cal move­ment are art forms which are real­ized in a time area and form time or­gan­isms. Of the ba­sic ele­ments of mu­sic (melod­ics, rhyth­mics, met­rics, har­mony, agog­ics, etc.), met­rics, rhyth­mics and agog­ics are mainly tem­po­ral de­ter­mi­na­tions.
Melod­ics and har­mony are at first glance more likely to pre­sent ele­ments of an aes­thetic con­tent, but they also are ul­ti­mately based on regu­la­ting fea­tures de­ter­mined by time with re­gard to tonal steps and tonal con­di­tions.

There is there­fore suf­fi­cient rea­son to search for bio­logi­cal time struc­tures in hu­mans which can be con­sid­ered for the mu­si­cal work and ex­peri­ence as equiva­lent or re­agent – what­ever their na­ture might be. Par­ticu­larly in view of the edu­ca­tional and thera­peu­tic re­sources of mu­sic, it is likely to be of im­por­tance to know in which way and where mu­si­cal-tem­po­ral func­tion or­ders and struc­tures are real­ized in the or­gan­ism.

The re­sults of mod­ern chro­no­bi­ol­ogy and chro­no­medi­cine have shown that the hu­man or­gan­ism does not only have a com­pli­cated in­te­rior de­sign in terms of space struc­ture, but also has a highly so­phis­ti­cated time de­sign which is built up from nu­mer­ous rhyth­mi­cal time struc­tures.

Il­lus­tra­tion 1 shows a spec­trum of the main types of rhyth­mi­cal func­tions which is ar­ranged ac­cord­ing to the pe­ri­odic du­ra­tion (loga­rith­mi­cally). It in­cludes approx. 2 x 12 oc­taves, from approx. one mil­li­sec­ond to an or­der of one year. The se­ries of given func­tions show that with an in­creas­ing pe­ri­odic du­ra­tion, the com­plex­ity of the rhythms grow, from the cel­lu­lar rhythms via the tis­sue and or­gan rhythms to the rhythms of com­plex sys­tems, and fi­nally to those which in­clude the en­tire or­gan­ism and even imply be­yond (re­pro­duc­tion and popu­la­tion rhythms). More and more par­tial func­tions are put to­gether for joint ac­tion, so that a hi­er­ar­chi­cal struc­ture exists, de­ter­min­ing, in what way the longer wave func­tions also in­clude the shorter ones in their rhythm.