In this article, I will simply direct you to a range of piano repertoire options in the hope that you discover something new in order to enhance your abilities, widen your awareness and increase your sensitivity.
Please note that this article has more links in it than any other article I have ever written so do explore them to learn more about the styles and musicians.
Before we dive into that, however, I would like to bring your attention to the 'musical sensitivity' part: If you like a piece of music, why? If you don't, why not? Knowing the theoretical and technical reasons behind the answer will help you to become more in-tune with your musical personality. Just saying "I (don't) like it" leaves a huge gap in your knowledge and awareness which is a great shame to the serious pianist.
The three most important components you should analyse your responses to are: tonality (major/minor, bluesy, filmy, romantic; the general emotional impact of the melody ), rhythm (do check out the link provided for rhythm; which ones do you like and dislike?) and harmony (chords and emotional connections).
Purely as a basic example without details or exceptions, I generally lean towards bluesy and romantic tonalities with swing 4/4 or 6/8 shuffle rhythms (of not too fast a tempo) and gentle, bluesy or soft-jazz harmony.
Here is an example (!) of what, to my ears, is pure honey and silk. Simple blues structure, elegant notes, not too heavy, not too fast, delicate, lovely chords, delicious bass line, shuffle rhythm, space, etc. If you do not like it, shame on you!
I'm joking. Just try to analyse why not and make a mental note of the reasons as to why exactly not. The only way a sculptor can complete his masterpiece is by removing what is not necessary, right?
Now let's get into the main point of the article. Play what?
I will divide piano music up into three periods: Classical, Jazz and Pop. I encourage you to go and discover the sub-divisions of these primary periods but will provide some starting points below in the form of YouTube links.
Please also recognise that each period's stylistic elements either remain to this day or were developed. That is to say, music is still written in the Classical and Jazz styles despite their popularity having faded to the prominence of pop; below are simply guidelines to get you started and not to be taken literally to the exact year.
The Classical period can generally be accepted as from c.1720-c.1890 or, to use some musicians as reference points: Bach's middle and later years (1685-1750), passing right through Mozart's life (1756-1791), involving the music of the almighty Beethoven (1770-1827) and closing with the passing of Liszt (1811-1886).
The Jazz period can generally be accepted as from c.1900-c.1960 or, to use some musicians as reference points: Scott Joplin and his Ragtime pieces (1868-1917), Cole Porter's huge contribution to the Great American Songbook (1891-1964) and Bud Powell with his enormous influence on jazz harmony (1924-1966).
The Pop period can generally be accepted as from c.1960-Present or, to use some musicians as reference points: Elvis Presley with his simple songs yet unique voice (1935-1977), The Beatles with their use of experimentation in form such as psychedelia and folk-pop (Lennon: 1940-1980/McCartney: 1942-Present), Freddie Mercury with his melodic rock band Queen (1946-1991) and Taylor Swift (1989-Present) whose style blends elements of country and pop-rock styles.
Already, you may have turned up your nose at a lot of what I have presented (I did!), either the name or the whole period (!) but you must dive into each period, explore what exists and surprise yourself. Also, accept that everyone has different tastes. I receive many emails from people wanting help with a Beethoven Sonata to how to play the theme tune from Titanic as sung by Celine Dion! Even beyond the above periods, you have world music from other countries, so go and listen to some Indian sitar or Peruvian panpipes if you wish!
Here are some examples of the above-mentioned musicians being performed on piano. Remember: why do you or don't you like each sample? Do your best to listen in full to each video for best results and please trust that I searched carefully for good versions which do the song justice. I am not associated with any of the channels links to. Take your time and listen with an open heart and mind and find the originals if you wish. This is about playing the music on piano, after all!
Now that you have quite a range of music to explore, and explore further I hope you will, have you identified your musical personality? Do you like simple chord progressions or mad jazz stuff? Do you like simple Mozart pieces or ridiculously complex Liszt rhapsodies? Are you attracted to major or minor tonalities? Lots of left hand action or more chord 'jabbing'? Do you want to accompany a singer (yourself or another) and play chords or rearrange complete pieces into a particular style you enjoy?
Whatever you do, do consider this article I wrote to give you the foundations both mentally and physically; the most useful videos are included.