https://memorisingmusic.wordpress.com/2013/04/04/interview-with-paul-roberts-pianist/

I gave an interview some years ago for the website Memorising Music. I still hold to the views I expressed here. 

Playing from memory for a professional pianist is the norm, though an increasing number of us nowadays are using the score. Liszt started it, as he started most things associated with the solo piano recital. (He coined the term 'recital' too, hitherto only used for literary readings, and he was the first to give entirely solo performances of piano music, unaccompanied by singers, instrumentalists, or acrobats.) Students at all major conservatoires are expected to perform the solo repertoire from memory, and particularly in America I get profuse apologies even in one-to-one lessons from students who need to use the score. Personally I am not worried in the slightest, unless I see it as a sign of compIacency and laziness - which is almost never the case. 

I do recognise and accept all the arguments for memorisation, but I have many misgivings too, as I explained in this interview. But then for me memorisation has always been difficult. A considerable amount of the repertoire I now play in public, especially my forays into Liszt over the past decade (and the B minor Sonata above all), I would never have tackled if I'd had the added stress of memory to contend with.

I often relate the story of Beethoven and his pupil Carl Czerny, a brilliant and natural pianist who mastered Beethoven's piano works effortlessly. Czerny played one of the master's works in public from memory and Beethoven was angry: how could his pupil be so careless of the master's instructions? From memory he was in grave danger of forgetting all the essential instructions and nuances of the score! 

Times have moved on. But I hope my own experiences, as I explain in this interview, might prove useful to those concerned by memorisation,  for amateur pianists and conservatoire students alike.