Here is what I do:

/pause 2, /stopsong
/pause 30, /cast <heal>
/pause 2, /stopsong
/cast <clarity>
/e sings a soothing tune

I put stopsong at the beginning so the macro kills any song currently being
sung(too lazy to stop current song). And I just let clarity keep singing at
end of macro in case I forget to restart the macro or in case I go afk -
clarity keeps going which I am more concerned about during downtime.

In general, I don't like long macros - once one starts, it must finish
before you can sing a different song. Maybe we should ask for an interrupt
command like /stopmacro to be able to stop a longer twist to get at the song
you really need NOW(i.e., mob pops and starts beating on medding cleric -
you want to charm it off them and can't since you just started the downtime
macro). So, my normal macros during a fight are:

/pause 2, /stopsong
/cast <song you want>

I then time it(based on current lag) to hit next macro for the next song
which stops the current song and starts the next. It saves you one
keystroke as you don't have to stop any songs if you create a similar macro
for each slot. So in a normal fight, I hit half as many hotkeys now and I
don't get the "you have not recovered" message anymore since I no longer can
jump the gun on starting the next song after I stopped the previous. Also,
if you miss a note, you don't have to wait to restart the macro as there is
no pause after song casting.

Also, for that where to go in 20's question - definitely Lake of Ill Omen.
It will take you to charm at 27 and beyond. My favorite charm target there
- Sabertooth Grimalkin, but you will test it out for yourself one day....
Good luck!

My two cents,

Piemur

PS - I just reread this and while I understand it, it is confusing with all
the stops/nexts/etc. Sorry. Hope it helps.