The command is /melody.
So to setup the macro:
e.g. /ho Twist /melody 1 2 3 4
So it'll repeat the 1 2 3 4 until you stop it or recast.
You can twist in others too or alternate. Its typically not fast enough to weave 5 songs. When I'm circle kiting, I also have it throw in a Selo's and then repeat the rest so selo's is recast roughly every 2 mins, allowing me to be semi-afk.
/melody 1 2 3 4 5 2 3 4 5 2 3 4 5 2 3 4 5 2 3 4 5 2 3 4 5 2 3 4 5
(or something like that)