A slur in piano music is two notes or more played together, one right after the other, in a smooth fashion. A slur marking, indicated by a curved line that begins at the first note of the slur and ends at the last, is considered an ornamental element in music. Slurs of more than two notes are often called runs. There is a technique for playing piano slurs that give the notes a particular flourish. Learning this technique will allow you to play piano slurs with precision.
Practice with a short slur. Any two notes on the piano will do. Until you get used to the technique, try staying with notes on the keyboard that are side by side. Start with middle C on your piano. Play the notes C, D, and E, using the second, third, and fourth fingers of your right hand. After you have gotten used to the way your fingers fall on these notes, you can begin playing slurs based around chords and arpeggios.
Play your three notes one after the other, with the first note emphasized and the second and third notes played softer. The object is to create a flowing sound. If you play all of the notes with the same dynamic, the result will sound choppy.
Practice playing the short slur forward and backward. Always start with your hand just above the keyboard and your wrist bent low, toward the keys. As you play the second note of the slur, bring your wrist back into a relaxed position, with your fingers dangling naturally toward the piano keyboard. Your wrist will feel completely relaxed by the time you lift your finger off the last note of the slur. When you have the hang of making the slur sound smooth and flowing, you can add notes and continue practicing. Practice the technique with first your right and then your left hand. Eventually you will be able to slurs with either one.