Other intervals are allowed if you are stuck, but nothing bigger than a 5th (only the bass part can leap an octave).Alto and tenor should either repeat the previous note or move by step (guideline).
Soprano should move either by step or by a third (guideline).With good voice leading, each part will move smoothly to the next note. Better still, try to actually sing these three upper parts - you are likely to find them quite awkward! Play each voice part through separately, and compare how they sound with the bass line, which IS musical. In this example, each individual chord has been correctly interpreted according to the figured bass, but the resulting individual voice parts are a terrible mess! If you only build chords vertically, by simply looking at the figures, you will end up with a mess horizontally - each voice part will jump around in a crazy, unmusical way. "Voice leading" refers to the way each separate voice part is constructed, note after note. Please click here for more information about our tutored harmony course. MyMusicTheory also offers a teacher-led harmony course which covers figured bass and harmonising a melody in a step-by-step way, with plenty of guided practice exercises. Most theory students find that having a teacher to help with figured bass is essential. In this section, we will exam the rules (unbreakable) and guidelines (break at your own risk!) which you need to memorize, in order to successfully realize a figured bass. Simply building up chords according the figures is not enough though, unfortunately! You need to abide by the rules of harmony as well, and aim to create a musical melody line (in the soprano voice). "Realizing" a figured bass means "making it real" or, filling out the four-part harmony by adding a tenor, alto and soprano part. Grade 6 Harmony Lesson A9: Figured Bass Rules for Realization Realizing a Figured Bass