the orchestra has how many primary instrument groups
Orchestra The typical symphony orchestra consists of four groups of related musical instruments called the woodwinds, brass, percussion, and strings (violin, viola, cello and double bass). Other instruments such as the piano and celesta may sometimes be grouped into a fifth section such as a keyboard section or may stand alone, as may the concert harp and electric and electronic instruments. The orchestra, depending on the size, contains almost all of the standard instruments in each group.
Musical instrument classification Later Sachs added a fifth category, electrophones, such as theremins, which produce sound by electronic means.[4] Modern synthesizers and electronic instruments fall in this category. Within each category are many subgroups. The system has been criticised and revised over the years, but remains widely used by ethnomusicologists and organologists.