The most critical element of the bassoon is the proper selection of an appropriate bocal. The bocal determines much of an instrument’s response, resonance and tonal characteristics. Each has its own unique characteristics that affect overall pitch and relative intonation of the instrument. Their seamless construction produces much greater resilience than a conventional brazed seam. Each bore comes in lengths 0-4 (4 being the longest).The bocal length moderately affects the overall pitch of the instrument, more so in the upper and middle registers. When seeking an appropriate bocal, it is common to begin the selection process with a number 2 length.