This standard specifies differentiated criteria for acoustic conditions and characteristics for spaces used for music rehearsal and performance. The criteria are specified for different types of music, regardless of the type of building in which the spaces are located. The standard provides criteria for room acoustics in spaces used for music rehearsal and performance, whether this is the primary use of the spaces or they are multi-purpose spaces. Together with the acoustic criteria, requirements are also given for room height, net room volume and net area. Criteria for acoustic conditions are differentiated on the basis of three music types: amplified music, quiet music and loud music. Definitions of these are given in clause 3. The standard is intended to be used in the planning of new buildings and the refurbishment of existing ones. The standard can also be used to assess the suitability of existing spaces for different musical purposes. The standard can be used for the adjustment of rooms and spaces whose primary purpose is not music rehearsal and performance. This can be done by using flexible solutions or by choosing a range of use which can be combined, for example in gymnasiums, classrooms, assembly halls, multi-purpose halls, etc. The criteria in this standard are not intended to be applied to large specialized concert halls, opera venues and similar spaces which are basically designed for concerts and performances. For music rooms, the limit values for background noise and sound insulation are given in clause 7 in NS 8175:2012. For other types of rooms and spaces whose primary purpose is not music rehearsal and performance, limit values for the background noise from technical installations are stated for the actual room types in class C in NS 8175:2012. The standard does not deal with the need for logistics, storage rooms for instruments and other key support functions relating to music rehearsal and performance: see [8], [19].