C#4. Bartolozzi, Bruno. New Sounds for Woodwind. London: Oxford University Press, 1971, p. 21. Different timbres of the same note.

Closed-dark:          Dark:         
 x x x | x x x        x x x | x x x F
Bb          F#               Bb

Closed-light:         Closed:
                                     F#
x x x | x o x          x x x | x x x F
B          F#         Bb

Light:                Open-light:
                          Eb
x x x | o x x F       x x o | x o o Ab
 c#                       D

Open:                 Open-dark:      
    Eb c#       
x x x | o o x F       x x x | x x x F  
    D  Bb               c#   Bb
                          D

C#4. Corey, Gerald. In Klimko, Ronald. Bassoon Performance Practices and Teaching in the United States and Canada. Idaho: University of Idaho, 1974, p. 65. For slur from C#4 to C#5. C#4. Same as Cooper p. 175 (no R. H. thumb F# key and B hole). C#5. Same as Cooper p. 331 (with L. H. thumb D speaker key?).

C#4:                 C#5:
              F#         Eb
x x x | o x x F      x o x | x o x

C#4. Ewell, Terry B. (02 Sept. 1994). For a rapid slur from C#4 to C#3 in a passage with the whisper key lock set:

C#3 (Cooper p. 72):     C#4:  
x  x  x  | o o o        x x x | o x x F
  c# wlock                wlock
  D

C#4. de Gomar, Juan. In Apfelstadt, Marc and Klimko, Ronald. Bassoon Performance Practice, Teaching Materials, Techniques and Methods. Idaho: University of Idaho, 1993 p. 55. Cooper p. 173.

x x x | x x x F
   c#  Bb

C#4. Groeling, Charles R. "Cultivating Bassoonists." The Instrumentalist 47/1 (August 1992): 50. Hardisty, Donald M. "Tuning those Bassoons: Part II--Tuning Individual Notes and Registers." The Instrumentalist 36/8 (March 1982): 72. Swanson, Robert. "Pictorial Bassoon Fingerings." Woodwind Magazine 4/1 (September 1951): 9. Cooper p. 172.

x x x | o x x F
   c#

C#4. Grossman, Arthur. (18 September 1996). For rapid slur from C#4 to A4 or B4:

x x o | x o o

C#4. Johnson, Betty. In Klimko, Ronald. Bassoon Performance Practices and Teaching in the United States and Canada. Idaho: University of Idaho, 1974, p. 63. Cooper p. 174.

x x o | x o o

C#4. Kirk, Edgar L. In Klimko, Ronald. Bassoon Performance Practices and Teaching in the United States and Canada. Idaho: University of Idaho, 1974, p. 66.

               F#
x x x | o x x (F)

C#4. Swanson, Robert. "Pictorial Bassoon Fingerings." Woodwind Magazine 4/1 (September 1951): 9.

x x x | o o o
   c#
  (D)

C#4. Swanson, Robert. "Pictorial Bassoon Fingerings." Woodwind Magazine 4/1 (September 1951): 9. Cooper p. 173.

x x x | x x x F
   c#  Bb

C#4. Swanson, Robert. "Pictorial Bassoon Fingerings." Woodwind Magazine 4/1 (September 1951): 9.

x x x | o o x F

C#4. Swanson, Robert. "Pictorial Bassoon Fingerings." Woodwind Magazine 4/1 (September 1951): 9. Cooper p. 171.

       c#
x x x | o o o
   (D)

Heckel-system bassoon fingerings by note name