I view Multi Riffs as a humanizer element of RB. To replicate what a Multi Riff does with audio requires a human player to do it as far as I know.
A Multi Riff is a selection of audio that the BIAB generation algorithm renders 7 selections for that audio snip. Any of the 7 snippets can be selected to replace the highlighted section. However, Multi Riff allows the user to insert any or all of those 7 snippets onto tracks and those snippets can then be cut/pasted edited or have Fx's just as any other audio can in a DAW. Pieces can be taken from each of the 7 snippets and comped into a single block of audio that can replace the highlighted audio or pasted elsewhere on that track or any other track in the song.
A different instrument can be selected and will replace the original audio and instrument for the highlighted section.
A MIDI file is rendered for each of the rendered multi riff snippets and placed on a track. An instrument patch can be assigned and to double the audio.
But here's why I call Multi Riff's a humanizing element. Note each multi riff generation is a unique rendition of the original rendered audio. This is much the same as a player will do with a 'punch in' during a live recording session.
In a recent thread in the RealBand Forum, a poster created a song over 330 measures in length. He uses MuseScore to make an XML file to open the song in RealBand. I haven't seen one of these songs but assuming he has multiple verses that likely repeat the same chord progression. I'll explain a way that were someone to wish to do so, they could create a dozen or more unique verses in just a few moments by taking advantage of the multi riff feature of RealBand.
1. Populate a Chord Chart that contains designated sections of your song. For instance, 1-4 INTRO; 5-12 VERSE; 13-20 CHORUS and 21-32 OUTRO
2. Insert Part Markers at the beginning of each section.
3. Activate the Snap to Beat Radio Button at Bar 5, the beginning of the VERSE Section.
4. From the Tool Menu: Block\Select Current Selection - this will select and highlight the VERSE section.
5. CTRL-C to copy the verse and from the window that opens, copy Events and Chord Symbols.
6. Set cursor at Bar 21: Edit\Insert Blank Bars into Song...
7. CTRL-V to paste the VERSE and edit part markers to reflect the verse insert at bar 21 and OUTRO is now Bar 29.
8. With the cursor at Bar 21, repeat Block\Select Current Selection to select and highlight VERSE2.
9. Generate Multi Riff and once the window opens with the 7 generated tracks, be sure to check the box Allow multiple riff selection and check the box on each riff to select all 7 riffs and click ok. You will be asked to select the track for the riff to be placed on. Select tracks and hit Ok.
Seven audio riffs will be generated and placed onto tracks you've selected. Seven MIDI riffs will also be generated and placed onto tracks beneath the audio riffs providing 14 total tracks that can be used to copy/paste fourteen additional and unique verses into the song. I've added a photo of an example.
I've posted several photos below and note how the algorithm allows the multi riff to begin in the prior measure before the edit and also extend beyond the ending measure of the edit. That can't be automatically done with a sample or loop as far as I'm aware and assures the edit should be seamless.
