Regardless whether you only sing karaoke once in a while or every night of the week, its good to have at least some sort of foundational knowledge. It also helps when you need to communicate your desires to others to have a common lexicon. After you finish reading, you should have just that.
Note: the pitch (frequency) and duration of a sound.
Root Note: The root note is generally the very first note played in a given song. Some songs have key changes, and when the change occurs, the first note of the phrasing determines the new key.
Key: The musical structure of a song, i.e. what notes you can play or sing during a song and not have it sound like free-form jazz—free-form jazz, as its name states, lacks the standard western structure present in most karaoke songs. For our purposes there are 7 major keys (A-G), 7 flat keys (Ab-Gb), 7 sharp keys (A#-G#), and 7 minor key for each of the standard (Am-Gm), Flat (Abm-Gbm), and Sharp (A#m-G#m) key for a total of 42 basic keys that may show up at the beginning of a Sound Choice song.
Half Step: The tonal distance between the current note or key and the sharp or flat above it or below it, or from a sharp or flat to the major or minor tone above it or below it. For instance, if a song is in A and you want to sing it in Ab, you ask to take it down one-half step. If you go up a half step, your new key would be A#. If a song is in C# and you want to sing it in the key of E, raise the key by three half steps. Don’t say one and a half whole steps—this is music, not mathematics, and you will likely confuse the KJ in addition to looking a bit silly.
Whole step: The tonal distance between the current note or key and the next Major or Minor, Sharp or Flat directly above it or below it. For instance, if a song is in A and you want to sing it in G, you ask to take it down one whole step. If you go up a whole step, your new key would be B. If a song is in C# and you want to sing it in the key of E#, raise the key by two whole steps. You can also say four half steps without confusing the KJ.
Scale: any sequence of musical notes in an ascending or descending order. For instance, ascending order for C major scale is C-D-E-F-G-A-B and descending order is C-B-A-G-F-E-D. There are a lot of adjectives that can be applied to scales such as diatonic, harmonic, pentatonic, etc. that are important if you are composing or playing music, but we aren’t, we’re singing karaoke.
Major Scale: A scale generally consisting of whole tones (i.e. ones that generally go up in whole steps). For Example: C major scale is C-D-E-F-G-A-B. Major scales tend to sound clear and open like Viva Las Vegas by Elvis Presley (G) or Down Under by Men at Work (D).
Minor Scale: A scale in which some of the notes (generally two or three) are reduced or raised by half tones. For Example: a C minor scale consists of C-D-Eb-F-G-Bb-Ab. Minor scales tend to sound dark, soft or even eerie like Minnie the Moocher by Cab Calloway (Cm) or Mother by Danzig (Bm).
Sharp Scale: Notes in C# scale are: C#-D#-E#-F#-G#-A#-B#. Notes in C# Minor: C#-D#-E-F#-G#-A#-B#. Sharp keys are popular in Country, Western, and Texas Blues arrangements giving it a bit of a twang, if you will, Texas Flood by Stevie Ray Vaughn is in F# and Big Iron by Marty Robbins is in C#m.
Flat Scale: Notes in Cb scale are: Cb: Cb-Db-Eb-Fb-Gb-Ab-Bb. Notes in Cb Minor: Cb-Db-Eb-Fb-Gb-Ab-B. The flat and flat minor scales tend toward darker tones as well like Red House by Jimi Hendrix (Bb) and Superstition by Stevie Wonder (Ebm).