Probably because there is an interval of an augmented second between the 6th and 7th scale degrees.
There are no sharps in the key signature, but in the harmonic minor there is a G#.
In A harmonic minor, there is just one sharp (G sharp).
Bb Harmonic Minor has 4 flats, since in the harmonic version of the scale the A flat (7th degree) is raised to A natural.
The harmonic minor scale is a minor scale with a major 7th (1 2 b3 4 5 b6 7). This creates a 3 half-step gap between the minor 6th and major 7th, resulting in a dark, exotic sound.
You cannot transpose from a major key to a minor key. You can change the key of a piece, but transposition must be either major or minor. Actually you can transpose from major to minor but it won't always sound right. First write down the chord functions for each chord in the major key (eg. I ii iii IV V VI viio). Then write down the interval of each melody note (eg. C over a G chord is a perfect fifth). Then for the minor key write out the chords using the chord functions as your guide. So if C was in major key, acting as I chord, in the key of Am you would have an Am chord. In minor keys we use a mixture of natural minor, harmonic and melodic minor which affects which chords you will use in your minor key. For example, in the key of Am the V chord might be E major (not E minor) using the G# from the melodic minor scale (or harmonic minor scale). It has a stronger resolution. For the melody use minor intervals instead of major intervals - so use minor 3rd instead of major 3rd, minor 6ths and 7ths. So if you had an E melody over C chord in major key you would have C melody note over Am chord. This doesn't always work but can get you started.
a harmonic minor
In a harmonic minor scale, the sixth of the scale is raised, so the step and a half is found between the fifth and sixth of the harmonic minor scale because normally, there is a whole step between the fifth and sixth of a minor scale. Raising the sixth adds another half step, so you get the step and a half.
The same as a harmonic minor on any other instrument. google it, you lazy bugger.
Dm
The 7th note (leading note) is raised by a semitone in a harmonic minor scale.
Natural minor, harmonic minor, and melodic minor
harmonic minor
A harmonic minor.
Major and Minor.
There are no sharps in the key signature, but in the harmonic minor there is a G#.
In A harmonic minor, there is just one sharp (G sharp).
two. first is F# in scale E minor second is D# has sharpened from D for E harmonic scale.