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NMR meets MUSICIANS

Melody "Happy birthday to you"

For this song, an approach was made of playing the melody by using chords instead of a monophonic sequence of tones. These chords may principally be created by a sample consisting of more than one resonance line. However, preparing such a sample is virtually impossible: the chemical shift differences of the individual sample components would have to exactly match musical tone intervals - a condition not achievable in practice.

Instead, I followed a different approach. When playing a chord on a guitar, the strings are excited not simultaneously but more or less as a sequence. Due to the short-spaced string excitations we hear a chord being played. Of course, each individual guitar string will give a distinct, slowly decaying tone ("relaxation" in the order of seconds). Unfortunately, this situation may not be emulated on an NMR spectrometer: during the acquisition time, a fixed reference frequency is applied which must be switched in order to hear a different tone. Hence, the NMR tones appear in a "staccato-like" manner. Nonetheless, a melody with a "chord-like" appearance may be heard.

As in the case of the former song, the diatonic tuning is employed. Due to the reasons outlined above the song may be played in any arbitrary tune. Again, the employed sample is acetone in CDCl₃.