The Liszt piano concertos are not the most difficult concerti composed. Yes they pose technical challenges, but remember, Liszt was a pianist, and many of his compositions have patterns that fit the hand are definitely accessible. I have studied the first two Liszt Concerti and nothing stands out as a true technical challenge. Someone suggested that they are not popular, but they are. The first is often played and in the standard repertoire of almost all professional concert artists.
Here are a couple things that make these pieces unique, then I'll go into the 3rd.
First Piano Concerto (Triangle Concerto)
One of the most unique characteristics of this piece is the use of triangle! This piece is considered the first piece to utilize this percussion instrument. Its first appearance is in a very catchy rhythmical pattern in the 3rd movement.
The second movement does what many thought that Liszt couldn't do! He composes one of the most lyrical melodies of the romantic generation and ends the movement with serenity and grace.
The piece is very virtuosic but everything is doable. The patterns have such challenges but nothing is impossible in Liszt. The orchestration happens to be very good for this piece. He balances the solo part out very well with the accompaniment. Remember, Liszt was one who started the tone poems so he understood how to compose for an orchestra. Chopin on the other hand was a poor orchestrator. Liszt was different than his romantic colleagues in terms of orchestration. He prefered clarity over dense textures like Brahms, Wagner and Berlioz used. Liszt wanted everything to be heard and for him less was better.
Like his Sonata, there are 4 movements but there are no breaks between movements. They move seamlessly with no pauses. The big bravura ending makes this piece an audience buster!
And the piece was premiered by Liszt at the piano and Berlioz conducting. That gave the piece a great send off but for what it is now, there have been many horrible displays of showmanship when pianists perform this piece. Still, it is a master piece.
Second Piano Concerto
Liszt took the challenge of creating a massive work for piano and orchestra that rivals Schubert's Wanderer Fantasy. A predecessor of Hindemith's Symphonic Metamorphosis, this piece takes a theme and Liszt transforms the theme (thematic transformation). This is not like a set of variations, more like morphing and mutating the theme. He did this in the b minor sonata as well. He originally titled the piece Concertant Symphonique as he thought it best represented what he was trying to do. Another influence of this piece was Weber's Konzerstucke for piano and orchestra.
Unlike the first which has movements, this piece is like Weber's as one long continuous piece that unfolds gradually. And unlike the first which is a pianist's dream of bravura and flash, the piano part in the 2nd concerto is a member of the orchestra. Hence the title Concertant Symphonique. Liszt regarded the piano part as a member of the orchestra and not a solo part. As well, the technical demands of this piece are much less than the first.
Part of the fame of this piece was Liszt's refusal to allow his students to perform it. Unlike the first which he always wanted his students to perform to demonstrate their agility on the keyboard, he felt many of his students could not pull off this piece because of the musical difficulties. Eventually his students and himself performed and the wait was worth it! By refusing performances of this piece he created the expectation of something great and to his surprise, his students' performance won great revues and acclaim.
Third Piano Concerto
Yes, often neglected and unknown to most of the audiences and pianist but a piece that is slowly gaining more popularity. This piece was premiered by Janina Fialkowska in 1990 with the Chicago Symphony. Ms. Fialkowska is one of the top Liszt interpretors in the world. It is said that this piece was composed before the first two concerto's but the date is inconclusive. An autograph says 1839 which is before the 1st two. Yet there are some claims it wasn't finished till 1847 so there is quite a bit of discrepency.
The concerto is very Lisztian but again like the 2nd is almost a piece for piano and orchestra. Liszt did not consider it a concerto for this reason and believed it was a tone poem for piano and orchestra. The structure, or lack of structure makes this piece difficult to understand. Unlike the 1st two which had audible forms and clear structure, the 3rd is some what confusing in that means. Some interesting syncopations take us to foreign keys, like a quasi-march in E-flat Minor. The piece might have more in common with the composer's tone poems than with conventional structure. What is unique is the 3 cadenzas which on their own could be etudes! They have pure bravura and the piece ends in whirlwind excitement much like the Totentanz! The use of Hungarian Folk Tunes and gypsy tunes is clear in this piece.
I'm not sure why this piece isn't performed a lot. It is quite enjoyable. I have read through it however my reasons for not learning it are time. It is a piece I would like to have in my repertoire however I have not been contacted to perform this piece. I have been asked to play other concerti leaving little time to work on this piece.
In defense of orchestras, many have been playing a lot of Mozart in the past 4 years to celebrate his 250th anniversary. Certain orchestras want to do certain music as well, NY Phil has been performing all the Mahler Symphonies in the past couple years for instance. As well if you contract a pianist for an engagement you select from their repertoire list. Simply put, many pianist do not have this piece in their repertoire. There are many great works by composers that are rarely performed but do have a small but loyal following.
and I've read the Alan Walker Liszt Books