RT Journal Article SR Electronic A1 Hána, Luboš T1 JF Aura musica YR 2013 VO 4 IS 2 SP 28 OP 33 UL https://aura.ujep.cz/en/artkey/aum-201302-0005.php AB The contribution deals with evolution of own choir from youth choir into an adult choir. It is based on 15 years experience with founding and conducting the choir. The author of the study tries to formulate choirmaster competences needed for conducting a choir. He shows the necessity of changing repertoir and the way of choir work to current social situation and abilities of its members. The level of the choir (which is mathematicaly "ungraspable") is described with hyperbole to Einstein Special Theory of Relativity.