A <u>soliloquy</u> is an instance during a play in which the character <u>speaks</u> his/her thoughts, opinions, or feelings aloud to the audience; thereby, it is not an <u>element of spectacle</u>.
The remaining terms: <em>"special effects", "gestures"</em> and <em>"dance"</em> are all <u>elements of spectacle</u> because they refer to resonant and striking visual aspects that enrich a play.