Yes, there are definitely some harsh sounding birds. The Australian raven with its loud caw is one as are the deafeningly noisy rainbow lorikeets. Rainbow lorikeets are brilliantly coloured - a flock is a visual feast - but are not pleasant neighbours for other birds because they toss the eggs and chicks out of nests to take over the hollows they like to breed in. Apart from their noise, they're also highly destructive of fruit crops so they're not the most popular of species here in the West where they aren't native but aviary escapes that have established themselves and are pushing out our local ringneck parrots. The red wattlebird is pretty harsh too. Even the famous kookaburra isn't exactly melodious.
But there are some lovely birdcalls too. The local ringneck parrot I mentioned above - known here as a twenty eight because of a distinctive part of its call, is one. I couldn't find a decent recording of it unfortunately. Then there's the Australian magpie that I wrote about a while ago. Its choirs on a moonlit night - they live in a family group of twenty or more - are sublime and, although they aren't nocturnal, they can't seem to resist a full moon. This is only a sample.
Another favourite of mine is the pied butcher bird and then there are the honey eaters, wrens and fairy wrens of which this fairy wren is only one of many. Beautiful, isn't it, and there are so many other different species, all unique and lovely but I'd be writing for hours to cover them all so I'd better stop.
Have a look here if you want to find out more. It's not exhaustive but gives a good starting point.