How Deep Is Your Love?
The question posed by Calvin Harris' recent hit single, How Deep Is Your Love, is a timeless one. The uncertainty of another's affection is a theme that has found cultural expression throughout every epoch of human history. Cutting to the core of mankind's romantic anxieties and jealousies, the question could just as easily have been asked 200 years ago as today. It signifies the peculiarity of our times, then, that the song, universal though its subject may be, is a "deep house banger" - i.e., a composition whose primary locus is the dance club, where the depth of another's love is likely not a pressing concern.
Nevertheless, it is inaccurate to characterize this song solely as an artifact of club culture. How Deep Is Your Love would be better described as a modern day art song, given the compositional and musical traits it shares with the tradition of lieder.
Made popular in 19th-century Germany by Franz Schubert, the lied, or art song, is a musical setting of a text - usually a Romantic poem - for voice and piano accompaniment. The lied remains at the core of classical vocalists' repertoire because it allows them to showcase their expressive range in settings more commonplace than the grand stage of the opera. Thus, the most distinctive characteristic about the art song is its cultivation of intimacy: vocalists often assume the position of tortured protagonists who divulge their most private feelings to their audiences through song. Already, this gives us a point of comparison - take a look at these two quatrains, one from Schubert's song cycle Die schöne Müllerin (The Beautiful Miller's Daughter), and the other from Calvin Harris' deep house banger.
It's difficult to compare the two objectively given our familiarity with CH's work, but at the very least, the fragments share several notable characteristics: 1) The implication of an amorous interest, 2) Allusions to nature ("moon," "starlight," "air"), and 3) A simplicity that lends itself easily to song.
The similarities are not solely lyrical, though. For one thing, the harmonic backbone of How Deep Is Your Love is based on mediant/submediant relationships: the chords that constitute the song are spaced not at the most common interval of the fifth, but rather at the third, meaning that successive chords share two notes in common. Schubert is known for having pioneered this harmonic maneuver, imbuing his music with a sense of longing and airiness that the mediant and submediant elicit. CH employs this same exact trope to give his song an unsettling, anxious quality.
Moreover, if you listen to the original mix, you'll notice that the song has both an instrumental introduction and an epilogue. Pure accompaniment is a rarity in modern day pop songs; it is, on the other hand, a common feature of art songs. The typical lied will open with a solo piano passage that sets the mood for the singer and close with one that summarizes the musical journey that the singer has taken. These accompanimental bookends define the musical premises of the art song - the motives, rhythms, melodies, and harmonies that define the piece. In CH's case, the opening of How Deep Is Your Love foreshadows the heavy reliance on the submediant harmony (an insistent C Major chord) mentioned above, setting up an unstable musical context into which the vocalist enters.
A final aspect of the art song which How Deep Is Your Love exhibits is the metamusical triangle it constructs between composer, performer, and audience. Throughout this post, we have presumed that How Deep Is Your Love is Calvin Harris' song, mostly because it is credited as such. From the modern pop-musical perspective, though, this is a very odd categorization. In general, we associate songs with their respective singers, who in this case is Ina Wroldsen. This is true in performance as well: in the following video of How Deep Is Your Love, you'll likely have trouble figuring out which one of the shadowy figures is actually CH.
Insofar as the vocalist serves as an emotional surrogate for the composer, then, How Deep Is Your Love is a great example of a modern day art song. Although he claims ownership over his song, CH requires a singer as an expressive proxy for his music, just like Schubert.
This brings us full circle to our original point about intimacy. Schubert and CH are two composers who have been noted for their "chronic shyness," and this timidity manifests itself in both the song's authorial construction and musical content. The truth about sensitive composers of any era is that they are capable of stirring up private feelings even in public settings. Fundamentally, How Deep Is Your Love is an art song because whether you're listening to it in a small room with close friends or in a giant wearhouse full of strangers, it has the power to make you feel like it's just you and someone else.