The submitted title was "Someone wrote a PhD thesis on bells". Sometimes a title like that has the virtue of getting an obscure, interesting submission onto the front page. The sin is venial when the submission is particularly good (and mortal when it's dreck, which alas is more often the case.)
Don't be so sure. At least for mathematicians, the "bell" may be just an excuse to make the subject cool. Many of the underlying problems are very general. For example, the inverse spectral problem (vibration modes of a complex shape) is the basis of the interaction between proteins, enzymes, and the huge molecules of cell walls. At the cell scale, Brownian motion shakes everything in all possible frequencies, but molecules can only vibrate at a specific set of frequencies (their spectrum). The act of "matching" different molecules happens when they have some common frequencies, often with localized modes of vibration.
You may think that you are just modeling church bells, but everything that you do has immediate application to the understanding of some organic chemical interactions, which are a deep mystery yet.