There is a great explanation of the definition of ostinato at Wikipedia.
In short:-
In music, an ostinato (derived from Italian: “stubborn”, compare English: obstinate) is a motif or phrase which is persistently repeated at the same pitch. The repeating idea may be a rhythmic pattern, part of a tune, or a complete melody.[1] Both “ostinatos” and “ostinati” are accepted English plural forms.
Here are some simple steps to get the improvisation started at your piano:
1. Create an ostinato or riff on the left hand
Once the riff is created, the basic element of a song is alredy done. We have the tempo, the rhythm, the catchy motif, the key etc .. you name it. It is easy to start with C major, play chord C for 4 bars and then Chord F for 4 bars repetitively. Refer the video.
2. Improvise melody on the right hand
Just simply play what we hear in our mind. Hitting any of the white key should be fine.
Reference :
Left-Hand Ostinato Patterns and Why They’re Perfect for Piano Improvisation!


{ 3 comments… read them below or add one }
Great help! Thanks a LOT!
This helped me out
Keep on with your skillz!
Cheers mate!
This is a nice start. I would love to get started with piano improvisation with the old standard ballads from the movies and Broadway of the 1940′s (my favorite era).
ex: If I loved You, Here’s That Rainy Day, etc. Music of Irving Berlin, Rodgers, Harry Warren, Jule Styne et al.
Regards, King from New York