Whooop !!! I spent several hours last night making macros from socials
and testing them. Ortez [sp?], the green orc in S Ro that heals himself
makes and excellent test subject BTW. Here is what I found with examples
listed below.
1. The shortest delay with my equipment and my DSL connection I could
get was for all practical purposes was 30.
I might get as low as 28, but start "losing" songs out of the
rotation when they don't have time to get
up.

2. The "/stopsong" command is essential and takes up an entire line by
itself. This has a limiting effect on how many songs your can
practically use. TWO. You CAN make a macro to sing 3 songs but the last
song will stay on and you will have to stop it manually. ....Well, there
is a way around it but if you don't have excellent timing you either get
the "Chat screen shivers" , when it shakes telling you you have
conflicting commands trying to be processed or the first song seems to
drop out of the rotation. My attempt at a single 3 song macro looks like
this. Resist messages did not stop the macro for continuing. Missed
notes MAY HAVE messed up the timing though... I do know that if I missed
a note the macro continued but the timing seemed thrown off enough that
the following song had trouble coming up. Not sure about this yet but
the solution was easy. Wait and hit the macro again to resynch.

3SNG (Macro name, 3 song)
/stopsong (to stop the last macro or song that is presumable still going
on)
/pause 30, /cast 3 (Fufils)
/stopsong
/pause 30, /cast 4 (Chant of Cold)
/stopsong
/cast 4 (Chant of Flame) Note.. no pause line needed.. it just plays on
anyway.

3. Suddenly last night I was able to twist FOUR songs 80 percent of the
time ! Never been able to do that with my machine before ! I think this
is because Macros remove any Keying errors and inefficiencies in timing
from my twisting :) The trick here was to set up 2 macros of 2 songs
each.... Run Song and 3 Chants. Run song might flicker but often the
icon would just stay up. I tried putting in a line like /say Hit it
again Sam ! as a visual indicator a macro was done but found that it
just took time away and you knew from the Icon greying/light when a
macro was finished.

BTL 1 (Label for "Battle song 1 macro)
/pause 30, /cast 8 (run song)
/stopsong
/pause 30, /cast 3 (Fufils chant)
/stopsong

BTL 2 (name of second macro)
/pause 30, /cast 4 (Chant of Cold)
/stopsong
/pause 30, /cast 5 (Chant of Fire)
/stopsong

4. They most popular use of the new macro will be the Run/Levitation
combination. You CAN keep the Tracking screen UP !!! using a macro
similar to the one below. Note, Lev FIRST (just in case) and the line to
give yourself a visual signal in the chat window the macro is done. I
found I had at lest 12 seconds grace before having to refresh the macro
if I got distracted. (Why do I feel that unless I want invisibility, I
am not going to be using the level 51 Selo's Song of Travel much ?)

FlyMe (Macro name)
/pause 30, /cast 6 (Levitation. Put first because I don't want my teeth
jarred :)
/stopsong
/pause 30, /cast 8 (Run song)
/stopsong
/say Fly Me ! (Chat Screen visual cue for when tracking screen covers
your song icons)

5. I also made Macros combining Heal Song, Mana Song and Niv's so I can
keep Mana up while healing the party which reduces keystrokes.
6. I found that "/pause 30" on a line by itself MAY be required if your
mixing Cast and Say type commands in some situations. The "/pause 30"
line ALWAYS has to be the first statement of a line even though it is
executed after the second statement. Whenever I tried to make a line
with more than 2 statements in it I got garbage. This should be further
investigated to be sure. Might just be me :)
7. Finally, if you want to switch songs between battles, say to drop
out a chant for a Heat shield, a simple right click on the icon brings
up the macro and you only have to retype one line.

I am sure more sophisticated programmers out there can come up with
better Macros :) but I hope this will help you get started.