Bag Notation

Abstract

Text-based bagpipe notation system and compiler

Overview

Bag notation is a text-based music notation, designed for bagpipes and optimized for human write-ability. The language itself was inspired by the concept of ABC notation, but streamlined for common bagpipe idioms.

A selection of the project documententation is available here as an overview. Visit the repository for the most complete and up to date information.

Quick links

Repository

Install: brew install p3l6/tap/bag-notation or Releases

More Documentation

Sample Tunes

Quick Reference pdf

Bag notation full file example

---
title: Scotland the Brave
trad
style: 4/4 March
---
|| xa+ vza.b/ xxcza xxce | xxh+ th+ vhe xxcza | rd+ xf.d/ xxce xxcza | xxb+ xxe+ te.f/ xe/.d//xc/.b// |
   xa+ vza.b/ xxcza xxce | xxh+ th+ vhe xxcza | rd+ xf.d/ xxce xxcza | xxb+ xa.b/ ta+ xxce           ||
|| xxh+ th+ vhe xxcza    | xxh+ th+ vhe xxce  | xxh+ th.g/ xf+ h.g/  | xfh tgf xed xcb                |
   xa+ vza.b/ xxcza xxce | xxh+ th+ vhe xxcza | rd+ xf.d/ xxce xxcza | xxb+ xa.b/ ta+.               ||

Running the compiler

• bag pdf something.bag -> writes output to something.pdf
• bag abc something.bag -> prints compiled abc source as output
• bag abc something.bag -> writes output to something.abc
• bag format something.bag -> prints formatted output
• bag format --dry-run something.bag -> prints nothing, but exits with status 0 only if no changes would be made
• bag format -i something.bag -> formats input by overwriting

All Language Symbols

This is a table of every character used in bag notation (with the exception of field values, which can contain any character except parentheses). All characters in the file are expected be from the ascii character set.

Semantic Embellishments

All embellishment patterns could be made by sequences of the literal gracenotes. However, this is tedious and error-prone in practice. Instead, the semantic embellishment markers signify a meaning, or intent, of standard expression. The specific gracenote pattern is inferred, based on the preceeding and following notes.

• x: A high gracenote (usually a G, but depending on context, perhaps a high A, etc)
• t: A low tap (often a low G)
• s: A light/softer low tap (disambiguates taps on notes like D, which may have a low G tap or C tap)
• v: A grip
• r: A throw
• n: The note, this is a stand-in for the following note (usually omitted, unless to disambiguate)

These six characters may be combined to indicate all common movements. Some common examples follow:

• xx: A doubling (Also could be written xnx, however the n is omitted for clarity)
• vz: A taorluath (A grip followed by an E grace)
• xt: A strike (alternatively, xnt A gracenote, theme note, then low tap)
• tt: A birl (The short one, as if playing from low A)
  • Other birl variations include:
    • ntt: A birl with a preceding low A
    • xtt: A birl with a high G gracenote at the beginning

While this scheme works very well for all the most common piping movements, there exist some rare movements which don’t have a good semantic binding and are outside its scope. For these, the literal gracenotes should be used instead. Such as: a crunluath with all low Gs (qpqzquq), cadences (yzp), edre on high G (zquq), etc.

Fields

Fields are an essential concept in bag notation. Fields give context to the notes, change the time signature, describe harmonies and variations, and much more.

A field can appear in the file header, label: value on a single line: or inline in the tune body, (label: value), with parentheses. A field without a colon is assumed to have no value. Some inline fields also have a shorthand symbol, which is used as that single character, without any parentheses.

All possible field labels are listed here. Most require values, unless stated.

Fields only valid in the tune header

• title: The tune’s title (Required for all tune headers)
• by: The tune’s composer
• trad: Set the tune as “Traditional”
  • Either trad or by is required for all tune headers
  • This is an alternative to by, for traditional with unknown composers
  • This field has no value
• arr: An arranger
• style: A tune style or rhythm
  • Values include: “March”, “4/4 March”, “Jig”, “Slow Air”, etc
  • A full list of valid values is in Sources/BagNotation/Models/Header.swift at mark “Create from Strings”
  • Some of these styles have implied time signatures, in which case the time field may be omitted
• rev: A revision date or number, appears in the page footer
  • Only one revision is used per file. If more than one tune has revision field, the first will be used for all pages, and the rest ignored
• newpage: Forces this tune to be placed on a new page, instead of possibly sharing a page with the preceeding tune
• dense: Compacts the spacing between lines and harmonies in the tune, useful when tunes almost fit together on a single page

Fields valid for both the tune header and inline

• time: The tune’s time signature
  • Required in the header, unless implied by the style field
  • When used inline, the current time signature changes at that point
• note: Set the base note length
  • Values: “quarter”, “eighth”, “sixteenth”, etc
  • Usually ommitted, as the default value is “eighth” and that works for most tunes
  • All notes in the tune will start at this length, and then the modifications (doubled, cut, dotted) will be applied
  • When used inline, the base length is changed for all following notes.
• tempo: Sets the tempo, as displayed on page output
  • Value should be an integer
  • When used inline, the new tempo will be notated at that point

Fields only valid inline

• h: Indicates a harmony line
  • Only valid at the very beginning of a line
  • Shorthand: &
• v: Set’s the current variation
  • Values: any string, usually like 2 or 2 of 4
  • Without a value, signifies the end of the variation. Note that variations will end at the end at the end of a line, and so this is only needed when the variation is only a few notes in the middle of the line
  • Shorthands: 0 1 2 3 4. As the most common variation names, these numbers can be used alone. A zero will end the current variation. ie. (v: 1) xa.b/ c (v: 2) xac e (v) is the same as 1 xa.b/c 2 xac e 0
• text: Adds an annotation to the following note
• hold: Adds a fermata on the following note
  • This field has no value
  • Shortand: ^. Remember that shorthands can appear inside note clusters, before the note’s embellishment (if any)
• rest: insert a rest
  • Values: a duration; the same as would follow a note pitch. eg + or // or +.
  • The value may be ommitted, in which case the base note lengh is used
  • The value may also be bar. This would create a whole bar rest, ie | (rest: bar) |. Note: do not put other notes in the bar, this is undefined.
• spacer: Similar to rest, but doesn’t print the rest symbol
  • Takes the same values as rest
  • Useful for filling out underful harmony bars, to line up the barlines. (Note: this is really a technical limitation in the underlying abc renderer, hopefully to be fixed someday)
• sharp: Marks the next note as a sharp accidental
  • This field has no value
  • Shorthand: ' (apostrophe) Remember that shorthands can appear inside note clusters, before the note’s embellishment (if any)
• flat: Marks the next note as a flat accidental
  • This field has no value
  • Shorthand: , (comma) Remember that shorthands can appear inside note clusters, before the note’s embellishment (if any)
• nat: Marks the next note as a natural accidental
  • This field has no value
  • Shorthand: = Remember that shorthands can appear inside note clusters, before the note’s embellishment (if any)
• chord: Adds a additional pitch to the next note
  • For example, (chord: c) xa++ creates a chord with A and C, where A is the primary pitch. The primary pitch used for determining semantic gracenotes related to the chord