The concert flute’s standard range is from B3 – D7 (forced up to F7).
In modern compositions microtones, for instance quarter tones, are called for. These can be played with ease using special fingerings.
A table of fingerings can be found in Robert Dick’s book “The Other Flute” (Multiple Breath Music Company, 1989). This book also contains a table of fingerings for a microtonal scale from Db4–G#6, which consists of 210 steps.