At the rank of tone group:
- the system of TONALITY — choice in the distribution of tone groups — realises the distribution of information units (textual metafunction);
- the system of TONICITY — choice in the placement of tonic prominence — realises the culmination of New information (textual metafunction);
- the system of TONE — choice in the major pitch movement — realises the system of KEY (interpersonal metafunction);
- the systems of TONE SEQUENCE and TONE CONCORD realise the systems of TAXIS and LOGICO-SEMANTIC TYPE (logical metafunction).
