Playing by ear does not have to be a pain. With a few simple secret tricks, it can be a real pleasure and joy. Also, did you know that playing the piano by ear can help you play other instruments like the guitar, violin, cello, flute, saxophone, and even the drums more easily? Learning how to play the piano is a great foundation for being musically competent with almost every other instrument.
What does it mean to play the piano by ear? It means to play the piano without much preparation or reading sheet music. It means to be able to hear a song, whether on the radio, at a concert, or on tv, and be able to play it on the piano without having to read sheet music or having to go through much preparation. Check out the video below of the "Top 10 Michael Jackson Covers" for examples of musicians that are playing music by ear.
Most of the musicians that you see in the video above are examples of musicians that can play instruments by ear - primarily the piano or the guitar. In addition, playing an instrument by ear has also helped them sing well. Although they are all singing Michael Jackson covers, they all make the song "their own" - meaning, they all make it unique to their own style. This is another advantage of being able to play music by ear and not being dependent on sheet music - if you have to be dependent on sheet music, then it is difficult to put your own personality and depth into the song.
If you've ever wanted to play one of your favorite songs, write a song, join or band, be a piano teacher or play the piano at an institution (like church), WITHOUT having to depend on sheet music, chords, or having to pay for lessons that can range anywhere from $25 - $60 an hour, then what you need to do is find a source that tells you straightforwardly how to do this. This way, you can learn at your own pace and save a lot of time and money on tedious and costly lessons.
Learn to Play Jazz and Jazz Chords by Ear Here

Learn to Play the Drums by Ear Here