This paper explores secondary school music teachers' current practice with regard to the organisation and assessment of composing at Key Stage 4. It draws on research undertaken on a nation-wide basis in England, via the use of two online surveys and face-to-face interviews. In terms of the organisation of classroom composition, the study found that the place of staff notation is currently under-theorised in terms of a developmental musical thinking tool, as opposed to what might be termed a "storage system". The research also found that ICT has brought composing to a wider range of participants. Considerably more time is spent on composing than other musical processes within a typical Key Stage 4 music classroom. The study found that music teachers are, in general, satisfied with the sorts of assessments which are being done at Key Stage 4. Examination Board criteria for assessing composing are universally utilised but there is a feeling that whilst these criteria are fit for purpose, they do not always reflect the effort that students have put into their work. Some styles which are "set" by examination boards are seen as being inappropriate for some students to access.