Billboard.BillboardData

Summary: A set of datatypes for representing Billboard chord sequence data See: John Ashley Burgoyne, Jonathan Wild, Ichiro Fujinaga, An Expert Ground-Truth Set for Audio Chord Recognition and Music Analysis, In: Proceedings of International Conference on Music Information Retrieval, 2011. (http://ismir2011.ismir.net/papers/OS8-1.pdf)

The BillBoard data representation

data BillboardData

The BillboardData datatype stores all information that has been extracted from a Billboard chord annotation

Constructors

BillboardData

Fields

getTitle :: Title

getArtist :: Artist

getTimeSig :: TimeSig

getKeyRoot :: Root

getSong :: [TimedData BBChord]

Instances

Show BillboardData

data Meta

Represents other metadata of the piece, i.e. the time signature and key root

Constructors

Metre TimeSig

KeyRoot Root

Instances

Show Meta

data BBChord

We wrap the Chord datatype into a BBChord type, so that we can augment it with Annotations and BeatWeights.

Constructors

BBChord

Fields

annotations :: [Annotation]

weight :: BeatWeight

chord :: Chord Root

Instances

Eq BBChord

Ord BBChord

Show BBChord

type Artist = String

Represents the artists of the piece

type Title = String

Represents the title of the piece

noneBBChord :: BBChord

A chord label with no root, shorthand or other information to represent a none harmonic sections

Billboard data utilities

Data access

getBBChords :: BillboardData -> [BBChord]

Strips the time stamps from BillBoardData and concatenates all BBChords

getBBChordsNoSilence :: BillboardData -> [BBChord]

Strips the time stamps from BillBoardData and concatenates all BBChords and removes the silence at the beginning and end of the song.

addStart :: Label -> BBChord -> BBChord

Adds a starting point of an Annotation Label to a BBChord

addEnd :: Label -> BBChord -> BBChord

Adds an end point of an Annotation Label to a BBChord

addLabel :: Label -> [BBChord] -> [BBChord]

Annotates a sequence of BBChords by adding a Start Label Annotation at the first chord and an End Label Annotation at the last chord. The remainder of the list remains untouched

addStartEnd :: Label -> BBChord -> BBChord

Adds both a start and an end Annotation Label to a BBChord

getDuration :: BBChord -> Int

Returns the duration of the chord (the unit of the duration can be application dependent, but will generally be measured in eighth notes) If the data comes directly from the parser the duration will be 1 for all BBChords. However, if it has been reduced with reduceBBChords the duration will be the number of consecutive tatum units.

getStructAnn :: BBChord -> [Annotation]

Returns the structural segmentation Annotations, given a BBChord

setChordIxsT :: [TimedData BBChord] -> [TimedData BBChord]

Sets the indexes of a list of TimedData BBChords (starting at 0)

Tests

isStructSegStart :: BBChord -> Bool

Returns True if the BBChord represents a starting point of a structural segment

isNoneBBChord :: BBChord -> Bool

Returns True if the BBChord is a noneBBChord, i.e. has not root note and no shorthand

isChange :: BBChord -> Bool

Returns True if the BBChord represents a chord Change (must be set beforehand, only the BeatWeight stored in the BBChord is examined)

hasAnnotations :: BBChord -> Bool

Returns True if the BBChord has any Annotationss and False otherwise

isEnd :: BBChord -> Bool

Returns True if this BBChord is the last (N) chord of the song

Chord reduction

reduceBBChords :: [BBChord] -> [BBChord]

The inverse function of expandChordDur: given a list of BBChords that all have a duration of 1 beat, all subsequent x BBChords with the same label are grouped into one BBChord with durations x. N.B.

>>> expandBBChords (reduceBBChords cs) = cs

also,

>>> (expandBBChords cs) = cs

and,

>>> reduceBBChords (reduceBBChords cs) = (reduceBBChords cs)

hold. This has been tested on the first tranch of 649 Billboard songs

expandBBChords :: [BBChord] -> [BBChord]

Given a list of BBChords that have a certain duration (i.e. the number of beats that the chord should sound), every BBChord is replaced by x BBChords with the same properties, but whit a duration of 1 beat, where x is the duration of the original BBChord

reduceTimedBBChords :: [TimedData BBChord] -> [TimedData BBChord]

Returns the reduced chord sequences, where repeated chords are merged into one BBChord, similar to reduceBBChords, but then wrapped in a TimedData type.

expandTimedBBChords :: [TimedData BBChord] -> [TimedData BBChord]

Similar to expandBBChords the inverse of reduceTimedBBChords

Showing

showInMIREXFormat :: ([TimedData BBChord] -> [TimedData BBChord]) -> BillboardData -> String

Shows the BillboardData in MIREX format, using only :maj, :min, :aug, :dim, sus2, sus4, and ignoring all chord additions

showFullChord :: ([TimedData BBChord] -> [TimedData BBChord]) -> BillboardData -> String

Shows the chord sequence in the BillboardData