Double Dutch again

Like Wordsworth's, my heart leaps up once in a while too; but unlike his, mine does so when I behold a name. Be it Araucaria or Paul, Enigmatist or Shed, my favourite compilers cause my heart to leap and I rub my hands in anticipation.

Today, the setter was Brendan. He always has an interesting twist in the crossword, and today was no exception. I realised there was a theme as soon as I solved the first and second down clues. After the doubles a few months ago, he has doubles on his brain again.

Eight of the down clues were themed, and the theme was reduplicates, both exact and ablaut. Before I tell you about them, here are some of the other gems.

Fetchingly enterprising types? (2-7) go-getters
The economy and the humour of this clue are lovely.

Like metal company found by sea (8) cobaltic

Lunatic craves celery when moon is blue (8,4) scarcely ever
Plain anagram, but nice with it.

Deride school with a grunt when put in another form (5,2,5) laugh to scorn
Misleading, but another anagram.

Fashionable style - with parts switched, mind (5,3) inner man
In and manner switched. Mind is the definition, and what a mind!

And he jokes about himself. Brendan and his like are such dogs (5,7) Irish setters

And here is the toughie. Introduction of expert cricket side's to sign on (12) prolegomenon
This is a gem. Introduction is the definition, and pro, leg, omen and on. This took me a while to solve.

Now for the theme clues, reduplicates: the six-letter long ones, four of them, were all exact reduplicates. The other four eight-letter long clues were ablaut reduplicates.

Salts forming deposit on teeth (6) tartar
He did this before, I grumbled to myself, but remembered that the definition was different.

Sweet smell from person in European city (6) bonbon
This is a clever one. BO in Bonn, and sweet is the definition.

Drum putting bird up (3-3) tom-tom
I've seen the piper's son being evoked for tom-tom, but this is the first time I came across the motmot backwards, and it is usually spelt momot.

Is able to preserve old dance (6) cancan
Remember my lesson about homonyms? This is a lovely example.

The other four were ablaut reduplicates:

Musical performance contributing to blessings on godchild (4-4) sing-song
This clue has the solution embedded.

Violent exchange, or what periodically interrupts it? (4-4) ding-dong
Heh!

Game between opponents at opposite ends of the table (4,4) ping pong

Greek in family circle no good for epic (4,4) king Kong
G and k between kin and o, and NG for no good; rather good though, right?

Cheers!