[Geoff Bacon]

You could use a laptop instead of the monitor.
Install MS on it and load your database on it (use MS Sync or Save/Restore operations to keep the databases the same)
He can then display the screen as he wants it.

In operation, set your iPad as the master and the laptop as a slave
Displaying songs on your iPad will display the same song on the laptop.
When you turn a page, so does the laptop.

Laptop still not big enough? Connect the external monitor to it (probably an HDMI cable).

Any laptop should have enough capability to do this (provided it runs MS)
You could even use an old ipad provided it runs MS and can connect to the monitor (I'm assuming that it's screen would be too small)

Main disadvantage is that you need to carry an extra device (and the cost if you don't already have one).

I recently experimented with my android tablet and an old windows laptop - it worked great.
To test it out before I bought a windows licence, I installed the free trial windows version on the laptop (this only handles a few songs as it is intended a a "try before you buy")
Sadly, the requirement never materialised but it showed it could be done.

Sounds as though want to run in landscape mode and he wants portrait.
This should be possible but would need checking (the mechansim isn't broadcasting an image to the slave, it is just telling it what songs to run from it's own database)

Hope this helps

Geoff