DD not into either so I had a hunt on their website and here is their info on music and drama found under Co-curricular - Performing Arts. I am aware of most of the events and I know there is a whole calendar of musical concerts. Having found what you are interested in, you could find the Head's Review (a summary of each week's event) for that week which are published weekly. They are found under the News - Head's Review. There is a Drama Scholars’ Production in February so keep an eye out as this should feature in the weekly review.
Re Music:
Roedean girls were entered for ten Grade 8 ABRSM exams over the last year, and five were awarded Distinction.
A wide range of ensembles come together every week, including Senior Strings, the Guitar Ensemble, the Roedean School Choir, as well as a number of chamber groups, such as a Piano Trio and two String Quartets.
Some pupils also attend Saturday music colleges in London.
Our musicians also go on to study Music at tertiary level at Oxford, Birmingham, Cardiff, Bristol, York, the Royal Academy of Music, and Trinity Laban.
And here is the same for drama:
There are three major productions each year:
The Winter Production in December is for girls in Years 8-13
The Drama Scholars’ Production takes place in February
The Summer Production in June is for those in Years 7-9.
Entry to all these companies is by audition and competition is fierce.
In addition, there are House Plays, run by girls, in early autumn, as well as a vast number of examination performances, the latter usually running through the Easter Term.
The School is also involved in writing schemes at a national level and is engaged with The National Student Drama Festival; girls are also current members of The National Youth Theatre.
Seems like I am doing a major sell but this gives you some detail. One thing to add is that there are several choirs at different levels. Also, she has friends in productions who are going on to do Drama at Uni. They do amazing open days and worth the travel - I wish we could go again as they are really fun (yes I know that sounds ridiculous).
Also I know Roedean has a reputation of Chinese students - this is changed under new Head although they still take a few at 6th Form. DD says there are now a large number of UK boarders from Year 7 (L3 I think). If you need anything else I could dig around the Parent Portal.