Sequenza VII contains 29 non-transposing pitches. Throughout the piece, these pitches are introduced. Some of the 29 pitches do not occur until close to the end of the piece. Sequenza VII begins with only one pitch available: B. Pitches are added gradually, enriching little by little the pitch language of the piece. Only by the last line (line 13) have all 29 pitches been stated. N.B. There is enharmonic equivalence throughout, i.e. C# = Db and so on.
5 pitches are not present at all in Sequenza VII: Low B, High B, Low C, High D and Low F
Thus, of the 34 pitches from low Bb to high G, Sequenza VII contains 29.
I recommend the oboist highlight in the score where each pitch is introduced. It's great to be aware of each new pitch as it enters.