"Maria"

"Cool"

"Jet Song"

"Something's Coming"

Looking at the selections of music above (and considering typical musical theatre music of the time), you might guess that they were instrumental lines involved in the accompaniment of a piece.  However, the sections above are all vocal lines in "West Side Story".  This show was one of the first times that tritones were an essential part of the melody and were accented.  However, a score made entirely of tritone leaps would probably end up sounding atrocious (not to mention much harder to perform).  What Bernstein also does is frequently use a raised fourth or a lowered fifth from the root of the key in the melody.  So he accomplishes the same thing by doing that.  It still adds the angst and excitement while making the melody have a line and a direction.  Lets look a bit more closely at some of the examples above.

"Maria"

In "Maria"the tonic key is E-flat.  The augmented note that is added is A natural (an augmented fourth from "do").  In this line he uses both the augmented interval between the first two pitches, and then uses the augmented pitch in a stepwise motion in the line.

"Cool"

In "Cool" the key is C major.  Again, Bernstein uses the augmented fourth interval.  In the first two measures that pitch is an F sharp because he is writing in C.  In measures five and six he has tonicized the fourth of the key, so he is writing in F.  However, in F, the augmented pitch is now a B natural.  In this example, Bernstein only uses the tritones in the interval of an augmented fourth.

"Jet Song"

In "Jet Song" the key is C Major but in this example Bernstein is writing in A Major so the tritone is a D sharp.

"Something's Coming"

In "Something's Coming" the key is D Major so the augmented pitch is a G sharp.  The first two times the pitch is used it is preceeded by a pitch three whole tones above it.  However, the rest of the time, the G sharp is used as an appagiatura or a passing tone.

These are just four of several examples throughout the entire score of "West Side Story" (both in the vocal line and in the accompaniment).