Anacrusis

Copyright © 2011 D. Michael McIntyre

This tutorial was written with Rosegarden 11.11.

Anacrusis occurs in music whenever the first note or notes precede the first downbeat in the piece. Typically a piece begins with a short, introductory "pickup" bar just before bar 1, and major sections of the composition continue to terminate and begin on this boundary in the middle of a measure, until the piece rounds out with a final bar that's short by the amount of the anacrusis that came in at the beginning.

"The Last Rose of Summer"

We can see this phenomenon in the Public Domain piece "The Last Rose of Summer," taken from the Mutopia Project. Here, the anacrusis occurs on the lyrics "'Tis the," which come in just before the first beat of bar 1 on "last."

Upon importing a MIDI version of this piece into Rosegarden, the first note in the MIDI sequence is at the start of bar 1, and all the bar lines are off compared with the original score.

It's easy to align the piece on the correct boundaries using the new "Create Anacrusis" feature, which automates what used to be a tricky and tedious process. First, select the segments you wish to realign. At least one of them must start exactly at the beginning of the composition. Next, use Segment -> Create Anacrusis, which takes you to a standard time entry dialog:

You need to examine the piece to figure out what duration to dial into this dialog. In this case, we have a dotted 8th note and a 16th leading up to the first downbeat, so we want an anacrusis of one quarter note. Conveniently, this happens to be the default amount, so we merely need to click OK and continue.

Rosegarden adds space to the beginning of the composition, and moves the segments, initial time signature, and initial tempo into that space. The piece is now aligned on the correct boundaries, and the final bar is short by the quarter note that started before the beginning.

Entering a 12/8 Example

The same technique can be used when entering notation from scratch. Let's say you are writing a piece in 12/8 with three distinct phrases, and you want to lead in with one beat of anacrusis, and leave the final bar short.

You can begin by drawing out the segments along the normal snap boundaries, to create something like this:

When the time comes to perform "Create Anacrusis", a bit of thinking is called for. One full beat in 12/8 is three 8th notes, which can also be expressed as a dotted quarter note. Select all three segments, enter a dotted quarter note into the time dialog, and now your piece is aligned as intended: