Sentence:  The Rachmaninoff Prelude No .12 , Op. 32 , for instance , gave her an opportunity to exploit one of her special facilities - the ability to produce fine deep-sounding bass tones while <WSD>contrasting</WSD> them simultaneously with fine silver filagree in the treble . 
Meaning of the word marked with <WSD> tags:  to show differences when compared; be different