Pourtnoy's warble

[Tan Cheng Ann <BA2319140@xxxxxxxxxxxxxxxx>]

Hi guys,
another question from me again...
can someone describe to me how Jerry Portnoy (sp?) did those
wahwah and warble effects on his playing in Eric Clapton's
FTC album? I just bought the album and spent the whole day
listening to it...chugging my walkman to the library and
everywhere. still not bored of it. EC's blues is intoxicating!
i heard that there were some discussions about this album in Blues-l
but i guess i found out too late and missed it. i followed Harvey
and Tim Wong's recommendation and bought it...no regrets!
(thanks!)

regarding air leakage in playing the harp...what do the other pros
have to say? more practice, no short cuts?

-cheng ann