I just had an email about what looks a really interesting concert at Sydenham Garden coming up:
On a glorious spring afternoon [2.30 - 5.30] Sydenham Garden will be opening its gates to the public for a unique musical event. Dreamt up by two students from the Guildhall School of Music & Drama, ‘Into the Garden’ is all about promoting local musicians and highlighting the work of Sydenham Garden.!
There's more about it on a dedicated web site for the concert here
I'm not sure if they're still looking for acts, but they have this on their site
We're looking for local acoustic acts to come and play in the garden on Sunday 15th April. We'll have three performance areas in the beautiful Sydenham Garden, where the audience can leisurely take in the sights and sounds. We'll be outdoors so long as it's acoustic we're interested.
and here's the contact form
At my allotments Open Days for the last few years, we've had Guildhall School of Music graduate jazz musicians entertaining us, and it works wonderfully. It should be great.
Just in case anyone doesn't know, Sydenham Garden is at 28a Wynell Road, Se23 2LW - here on Google StreetMap