Definitely chromatic. I teach using the alternate (fork) fingering for high E and F, add F sharp with the fork F and high F sharp key. It helps to start the note with air instead of tongue at first. If you can get a G sharp, slide down to the G from there. Be sure you can play the overtone series on low B flat, B, C C sharp to the octave, P5, P4 or you will have minimal success. Good luck