 Slash notation and rhythmic notation may both be used in the same piece, for example, with the more specific rhythmic notation used in a section where the horn section is playing a specific melody or rhythmic figure that the pianist must support, and with slash notation written for the pianist for use underneath improvised solos.Nashville notation or Nashville Number System is a method of writing, or sketching out, musical ideas, using numbers in place of chord names.For example, in the key of C major, the chord D minor seventh can be written as "2−7", "2m7", or "ii7".