Add links and update info page 04

1 files changed, 29 insertions, 12 deletions

diff --git a/2020/info/04.md b/2020/info/04.md
index 00b04224..db8ac0ec 100644
--- a/2020/info/04.md
+++ b/2020/info/04.md
@@ -14,41 +14,58 @@ distribution of musical scores. In this talk, I begin with an overview
 of the LilyPond syntax and move on to showcase ways for producing
 algorithmic compositions and music books using Make, Org and
 LilyPond-mode.
-<!-- from the pad --->
 
+Source files and other materials can be found at
+<https://gitlab.com/jagrg/emacsconf-2020> and
+<https://gitlab.com/drumbook>.
+
+<!-- from the pad --->
 
 # Questions
 
 ## Do you have any thoughts on generating scores in chant notation (neumes)?
-I'm not familiar with chant notation, but I know there's information on the manual.
+
+I'm not familiar with typesetting chant notation, so I suggest reading
+this specific section of the manual for information.
 
 ## Do you use this to compose or to write up compositions&#x2026;?
-No and yes. I use pencil and paper to compose the first draft. Then I move to Emacs to input the notes. Either way it's certainly possible to compose from Emacs directly, especially if you're doing this programatically, so I guess it depends on what you're trying to do.
 
-## Can one use MIDI/USB instruments (like keyboards) to input Lilypond? For example for note heighs?
+No and yes. I use pencil and paper to compose the first draft. Then I
+move to Emacs to input the notes. Either way it's certainly possible
+to compose from Emacs directly, especially if you're doing this
+programatically, so I guess it depends on what you're trying to do.
+
+## Can one use MIDI/USB instruments (like keyboards) to input Lilypond? For example for note heights?
 
 [Don't know about emacs, but Frescobaldi supports MIDI input.]
 
-There is a package called midi-kbd which creates keyboard events from MIDI input, so I believe the answer is yes, but I don't own a MIDI controller, so I haven't tried it.
+There is a package called `midi-kbd` which creates keyboard events
+from MIDI input, so I believe the answer is yes, but I don't own a
+MIDI device, so I haven't tried it.
 
 ## Did you ever write huge scores (BigBand/Orchestra) in Emacs?
+
 Never, but that's certainly possible.
 
-## Is there decent OCR for handwritten music→Lilypond?
-I'm not sure, but if the OCR works with MusicXML, then you can use the musicxml2ly command to convert the xml file to a LilyPond file.
+## Is there a decent OCR for handwritten music→Lilypond?
+
+I'm not sure, but if the OCR works with MusicXML, then you can use the
+`musicxml2ly` command to convert the XML file to a LilyPond file.
 
 ## What shell are you using with the fancy autocomplete?
+
 Zsh with fzf.
 
-## Do you use any kind of Emacs to MIDI interface besides exporting MIDI from lilypond?
+## Do you use any kind of Emacs to MIDI interface besides exporting MIDI from LilyPond?
+
 No.
 
 # Notes
 
--   Emacs + Lilypond
--   Similar to LaTeX — has its own file format and syntax, can also export to MIDI
+-   Emacs and LilyPond integration
+-   Similar to LaTeX — has its own file format and syntax, and can export to MIDI
 -   (info "(lilypond-learning) Top")
--   The contrast between background and foreground is a little too weak.
--   Uses LilyPond-mode, flycheck
+-   Low contrast between background and foreground
+-   Uses LilyPond-mode and flycheck
 -   <https://orgmode.org/worg/org-contrib/babel/languages/ob-doc-lilypond.html>