It derives from African, pentatonic and also from Arabian scales. Minor third, augmented fourth (minor seventh too) are characteristics blues notes. It is one of the best jazz and more used scales in this style.
In improvisation, you can use it on major seventh chords too but pay attention to blues notes: play them like passage, grace, or turnings notes.
Every instrumentalist (a singer too) should play them very often, above all the ones in less used tonalities (G#, C# and so on) being less common in solos. Pay attention not to overindulge in this scale because hearing it is so boring the same sonority too much.
Moreover, blues scales are very strong and can be recognized at once; they are nice and can be considered the top ones in solos but are to be used a little in order not to tire a listener’s ear.
Notes in these scales can be used freely enough compared to the chord in which they are. It means the melodic lines based on it, can be independent from chord. If you want to understand this concept better I suggest you to study the most important page of this site, where the construction of melody in improvisation and in composition is described.
Blues scales in music styles
Blues scales are used in many musical kinds (for example in blues, jazz, rock and roll, funk, soul rhythm and blues, dance, pop…).
Blues scales are the most famous sounds of the XX century music. Almost all music genres being born in the last hundred years come from blues (above all in not-classical music).
It is my favorite style, especially when it is mixed with jazz, pop and dance.
Learn all blues and other music scale charts
Play and learn by ear all 12 blues scales. Then begin improvising on a major or minor blues structure, just using blues scale notes. Blues scales play very well on dominant chord. A big jazz musician wrote a sentence in his book and he was particularly struck by it when I was eighteen and it simply said that “Blues is the Soul of Jazz”. So it can be considered one of the most used and suitable jazz scales.