The quick, intuitive, and entertaining Jazzhacker Scales App is a reference and practice tool for guitar players of all skill levels playing any genre of music, and for all music fans. The Jazzhacker Scales App features a library of 340 images of the most popular and useful scales and modes. These copyrighted images provide, at a glance, scale names, scale formulas, scale notes, and a depiction of a guitar fretboard showing the locations of all notes in the scale. The user quickly and easily selects one or more images to be displayed, or selects all scales in a particular key, or any one scale in all keys, or all scales or all keys, etc. The user specifies a time duration to display each image (5 seconds to 60 minutes) and the resultant slideshow (which may be run in a full-screen mode) runs when played. The user may pause and restart the slideshow at any time. The user may also quickly and easily build a custom playlist (with up to 360 images) to create a practice session or to model songs to play, etc. The playlist is also played as a slideshow and is saved with the app until cleared by the user. Scales and modes are crucial building blocks of music and the patterns formed on guitar fretboards by scales and modes become familiar with practice. The Jazzhacker Scales App provides a reference for these scales and modes and does so in an entertaining manner. Scales: Major (Ionian) Whole-Tone Lydian Lydian Flat-Seven Mixolydian Major Pentatonic Major Blues Melodic (Jazz) Minor Dorian Harmonic Minor Natural Minor (Aeolian) Diminished (Whole-Half) Diminished (Half-Whole) Super Locrian Phrygian Locrian Blues w/Major Third Minor Pentatonic Minor Blues Half Diminished ALL SCALES Keys: A, A#, Bb, B, C, C#, Db, D, D#, Eb, E, F, F#, Gb, G, G#, Ab, ALL KEYS