As an experiment I wrote this simple ABC file:
X:1
T:C Scale
L:1/4
M:4/4
K:C
C2 D E | F G A B | c4- | c4 |]
I loaded this into MuseScore using the ABC import plugin. From here I output my simple score as a PDF which I have attached below.
Next I saved the file as musicXML:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE score-partwise PUBLIC "-//Recordare//DTD MusicXML 2.0 Partwise//EN" "http://www.musicxml.org/dtds/partwise.dtd">
<score-partwise>
<movement-title>C Scale</movement-title>
<identification>
<encoding>
<software>MuseScore 1.3</software>
<encoding-date>2015-06-18</encoding-date>
</encoding>
</identification>
<defaults>
<scaling>
<millimeters>7.05556</millimeters>
<tenths>40</tenths>
</scaling>
<page-layout>
<page-height>1683.78</page-height>
<page-width>1190.55</page-width>
<page-margins type="even">
<left-margin>56.6929</left-margin>
<right-margin>56.6929</right-margin>
<top-margin>56.6929</top-margin>
<bottom-margin>113.386</bottom-margin>
</page-margins>
<page-margins type="odd">
<left-margin>56.6929</left-margin>
<right-margin>56.6929</right-margin>
<top-margin>56.6929</top-margin>
<bottom-margin>113.386</bottom-margin>
</page-margins>
</page-layout>
</defaults>
<credit page="1">
<credit-words default-x="595.276" default-y="1627.09" font-size="24" justify="center" valign="top">C Scale</credit-words>
</credit>
<part-list>
<score-part id="P1">
<part-name></part-name>
<score-instrument id="P1-I3">
<instrument-name></instrument-name>
</score-instrument>
<midi-instrument id="P1-I3">
<midi-channel>1</midi-channel>
<midi-program>0</midi-program>
<volume>78.7402</volume>
<pan>0</pan>
</midi-instrument>
</score-part>
</part-list>
<part id="P1">
<measure number="1" width="328.26">
<print>
<system-layout>
<system-margins>
<left-margin>0.00</left-margin>
<right-margin>0.00</right-margin>
</system-margins>
<top-system-distance>180.00</top-system-distance>
</system-layout>
</print>
<attributes>
<divisions>1</divisions>
<key>
<fifths>0</fifths>
<mode>major</mode>
</key>
<time>
<beats>4</beats>
<beat-type>4</beat-type>
</time>
</attributes>
<note default-x="79.15" default-y="-50.00">
<pitch>
<step>C</step>
<octave>4</octave>
</pitch>
<duration>2</duration>
<voice>1</voice>
<type>half</type>
<stem>up</stem>
</note>
<note default-x="189.15" default-y="-45.00">
<pitch>
<step>D</step>
<octave>4</octave>
</pitch>
<duration>1</duration>
<voice>1</voice>
<type>quarter</type>
<stem>up</stem>
</note>
<note default-x="257.91" default-y="-40.00">
<pitch>
<step>E</step>
<octave>4</octave>
</pitch>
<duration>1</duration>
<voice>1</voice>
<type>quarter</type>
<stem>up</stem>
</note>
</measure>
<measure number="2" width="277.53">
<note default-x="12.00" default-y="-35.00">
<pitch>
<step>F</step>
<octave>4</octave>
</pitch>
<duration>1</duration>
<voice>1</voice>
<type>quarter</type>
<stem>up</stem>
</note>
<note default-x="77.98" default-y="-30.00">
<pitch>
<step>G</step>
<octave>4</octave>
</pitch>
<duration>1</duration>
<voice>1</voice>
<type>quarter</type>
<stem>up</stem>
</note>
<note default-x="143.97" default-y="-25.00">
<pitch>
<step>A</step>
<octave>4</octave>
</pitch>
<duration>1</duration>
<voice>1</voice>
<type>quarter</type>
<stem>up</stem>
</note>
<note default-x="209.95" default-y="-20.00">
<pitch>
<step>B</step>
<octave>4</octave>
</pitch>
<duration>1</duration>
<voice>1</voice>
<type>quarter</type>
<stem>down</stem>
</note>
</measure>
<measure number="3" width="232.69">
<note default-x="12.00" default-y="-15.00">
<pitch>
<step>C</step>
<octave>5</octave>
</pitch>
<duration>4</duration>
<tie type="start"/>
<voice>1</voice>
<type>whole</type>
<notations>
<tied type="start"/>
</notations>
</note>
</measure>
<measure number="4" width="238.69">
<note default-x="12.00" default-y="-15.00">
<pitch>
<step>C</step>
<octave>5</octave>
</pitch>
<duration>4</duration>
<tie type="stop"/>
<voice>1</voice>
<type>whole</type>
<notations>
<tied type="stop"/>
</notations>
</note>
<barline location="right">
<bar-style>light-heavy</bar-style>
</barline>
</measure>
</part>
</score-partwise>
Finally I exported the file in compressed MuseScore format (mscz), which I have also attached below.
By way of comparison file sizes are listed below:
abc | 61bytes |
xml(uncompressed musicXML) | 5.1kB |
mxl(compressed musicXML) | 1.5kB |
mscz | 1.4kB |
pdf | 10.6kB |
IMO ABC is clearly the most efficient format for exchange. It is also much easier on the eye than musicXML. That said, the other formats are efficient carriers with relatively small file sizes. The pdf file has the largest file size and also requires Acrobat reader, or other software to be read.
The conclusion here is that the existing options for file attachment are capable of working with a wide variety of formats and perhaps the most efficient mechanism for exchange would be to include ABC as code, with an attached image file (jpg or png) for reference.