Playmeans: Inclusive and Engaging Data Science through Music

Figures & data

Table 1 Data dictionary describing the variables displayed throughout the Playmeans app (acquired from Spotify public API).

Variable	Description
Track Name	Name of the Song
“Energy”	“Energy is a measure from 0.0 to 1.0 and represents a perceptual measure of intensity and activity. Typically, energetic tracks feel fast, loud, and noisy. For example, death metal has high energy, while a Bach prelude scores low on the scale. Perceptual features contributing to this attribute include dynamic range, perceived loudness, timbre, onset rate, and general entropy.”
“Duration”	“The duration of the track in milliseconds.”
“Acousticness”	“A confidence measure from 0.0 to 1.0 of whether the track is acoustic. 1.0 represents high confidence the track is acoustic.”
“Danceability”	“Danceability describes how suitable a track is for dancing based on a combination of musical elements including tempo, rhythm stability, beat strength, and overall regularity. A value of 0.0 is least danceable and 1.0 is most danceable.”
“Tempo”	“The overall estimated tempo of a track in beats per minute (BPM). In musical terminology, tempo is the speed or pace of a given piece and derives directly from the average beat duration.”
“Speechiness”	“Speechiness detects the presence of spoken words in a track. The more exclusively speech-like the recording (e.g., talk show, audio book, poetry), the closer to 1.0 the attribute value. Values above 0.66 describe tracks that are probably made entirely of spoken words. Values between 0.33 and 0.66 describe tracks that may contain both music and speech, either in sections or layered, including such cases as rap music. Values below 0.33 most likely represent music and other non-speech-like tracks.”
“Liveness”	“Detects the presence of an audience in the recording. Higher liveness values represent an increased probability that the track was performed live. A value above 0.8 provides strong likelihood that the track is live.”
“Loudness”	“The overall loudness of a track in decibels (dB). Loudness values are averaged across the entire track and are useful for comparing relative loudness of tracks. Loudness is the quality of a sound that is the primary psychological correlate of physical strength (amplitude). Values typical range between –60 and 0 db.”
“Valence”	“A measure from 0.0 to 1.0 describing the musical positiveness conveyed by a track. Tracks with high valence sound more positive (e.g., happy, cheerful, euphoric), while tracks with low valence sound more negative (e.g., sad, depressed, angry).”
“Instrumentalness”	“Predicts whether a track contains no vocals. ‘Ooh’ and ‘aah’ sounds are treated as instrumental in this context. Rap or spoken word tracks are clearly ‘vocal.’ The closer the instrumentalness value is to 1.0, the greater likelihood the track contains no vocal content. Values above 0.5 are intended to represent instrumental tracks, but confidence is higher as the value approaches 1.0.”

Fig. 1 Setting up the Spotify “Dev” account.

Fig. 2 Obtaining Client ID and Client Secret upon creating the Spotify “Dev” account. The ID and secret in this image are arbitrary and are for illustrative purposes only.

Fig. 3 Logging in to Playmeans.

Fig. 4 Searching for an artist.

Fig. 5 Data loaded after being pulled from Spotify data repositories in real time. Hovering over the column names displays their definitions.

Fig. 6 Histograms of the various data fields are displayed upon selecting the radio buttons in the left panel. Hovering the mouse over each histogram and clicking anywhere within the vertical bars plays a free, 30-second preview of the track falling into the corresponding bin (unless a preview is unavailable from Spotify).

Fig. 7 Interactive profile plot (a) with audio and Static Profile plot (b) without audio. The value of “k” is set using the slider within the tab. In both plots the horizontal axis corresponds to the variables that were used in clustering, and the vertical axis designates the cluster number. In plot (a) the sizes of “emojis” and in (b) the colors are based on the magnitudes of the centroids. In plot (a) hovering over the plot and clicking plays a free, 30-second preview of a track randomly selected from a cluster that was clicked (if a preview is available from Spotify).

Fig. 8 Elbow plot after performing K-means clustering with values of “k” ranging from 1 to 10. The horizontal and vertical axes correspond to the value of “k” and the within-cluster sums of squares, respectively.