Opus 30 is the first collection of Mazurkas in which Chopin did not indicate metronome tempi. Among the earlier ones provided with such indications, there are two marked as Vivace, the Mazurka in E, Op. 6 No. 3, 
= 60 and the Mazurka in B
, Op. 7 No. 1, = 50; however, there is not a single one marked as Allegretto. Nevertheless, the metronome tempi of the Mazurkas determined as Lento ma non troppo, hence seemingly slower than Allegretto, deviate from them to such a small extent – the Mazurka in E minor, Op. 17 No. 2, 
= 144, the Mazurka in A minor, Op. 17 No. 4, = 152, that one could assume that the intended change of tempo was very small and that the new indication was rather to point to the character of the music, clearly different from both outermost Mazurkas, which also include Allegretto in the tempo/character marking.
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category imprint: Differences between sources; Corrections & alterations
issues: Changes of tempo markings
notation: Verbal indications