Exploring New Sounds in Stereo is the first of the typical Esquivel albums from which the CD compilations draw heavily.
There is a lot to recommend it.
"Whatchamacallit" is probably his second best-loved tune (released also as a single backed with the non-LP track, "I Feel Merely Marvelous").
The track features the ondioline, an electronic-organ-like instrument often associated with the theremin.
And on Exploring New Sounds in Stereo, there is indeed theremin in Esquivel's spacy treatment of "Spellbound" (from the movie of the same name).
Other highlights include the exotic "Bella Mora," the cheesy "My Number One Love," and "The 3rd Man Theme." The album also has slightly different arrangements than the monaural Exploring New Sounds in Hi-Fi.