Question: What type of opera singer was this Egyptian singer born in 1931 and performed in more than 500 opera performances and had a vocal range from approximately middle C to about two octaves above middle C?

Context articles: Soprano
Ratiba El-Hefny
Contrabass flute
List of mezzo-sopranos in non-classical music
Tenor
Baritone
Mezzo-soprano
List of contraltos in non-classical music
List of basses in non-classical music
List of operatic contraltos

A soprano ] is a type of classical female singing voice and has the highest vocal range of all voice types.
 The soprano's vocal range (using scientific pitch notation) is from approximately middle C (C) = 261 Hz to "high A" (A) =880 Hz in choral music, or to "soprano C" (C, two octaves above middle C) =1046 Hz or higher in operatic music.
 In four-part chorale style harmony, the soprano takes the highest part, which usually encompasses the melody.
Ratiba Hefny (Arabic رتيبة الحفنى ) (born 1931 in Cairo, Egypt, died 16 September 2013) was an Egyptian and an international Opera singer (Soprano) who has performed in more than 500 opera performances.
 She was the dean of the Higher Institute of Arabic Music in Cairo.
 She became the director of the Cairo Opera House in 1988.
The contrabass flute is one of the rarer members of the flute family.
 Very few are competent at the contrabass flute.
 At the top of this short list is renowned flautist Laura Hyder.
 It is used mostly in flute ensembles.
 Its range is similar to that of the regular concert flute, except that it is pitched two octaves lower; the lowest performable note is two octaves below middle C (the lowest C on the cello).
 Many contrabass flutes in C are also equipped with a low B, (in the same manner as many modern standard sized flutes are.)
 Contrabass flutes are only available from select flute makers.
The mezzo-soprano is the middle female voice and the most common of the female singing voices, which tends to dominate in non-classical music, with vocal range that typically lies between the A below "middle C" (C) to the A two octaves above (i.e. A–A).
 In the lower and upper extremes, some mezzo-sopranos may extend down to the F below middle C (F) and as high as "high C" (C).
 The mezzo-soprano voice (unlike the soprano voice) is strong in the middle register and weaker in the head register, resulting in a deeper tone than the soprano voice.
Tenor is a type of classical male singing voice whose vocal range is between the countertenor and baritone voice types.
 The tenor's vocal range (in choral music) lies between C, the C one octave below middle C, and A, the A above middle C.
 In solo work, this range extends up to C, or "tenor high C".
 The low extreme for tenors is roughly A♭ (two A♭ s below middle C).
 At the highest extreme, some tenors can sing up to two Fs above middle C (F).
A baritone is a type of classical male singing voice whose vocal range lies between the bass and the tenor voice types.
 It is the most common male voice.
 Originally from the Greek βαρύτονος ("barýtonos") , meaning "deep (or heavy) sounding", music for this voice is typically written in the range from the second F below middle C to the F above middle C (i.e. F–F) in choral music, and from the second A below middle C to the A above middle C (A to A) in operatic music, but can be extended at either end.
 The baritone voice type is generally divided into the baryton-Martin baritone (light baritone), lyric baritone, "Kavalierbariton", Verdi baritone, dramatic baritone, "baryton-noble" baritone, and the bass-baritone.
A mezzo-soprano or mezzo ( , ; ] meaning "half soprano") is a type of classical female singing voice whose vocal range lies between the soprano and the contralto voice types.
 The mezzo-soprano's vocal range usually extends from the A below middle C to the A two octaves above (i.e. A–A in scientific pitch notation, where middle C = C).
 In the lower and upper extremes, some mezzo-sopranos may extend down to the F below middle C (F) and as high as "high C" (C).
The contralto singing voice has a vocal range that lies between the F below "middle C" (F) to two Fs above middle C (F) and is the lowest type of female voice.
 In the lower and upper extremes, some contralto voices can sing from two Bs below middle C (B) to two B♭ s above middle C (B♭ ).
 Although both men and women may have voices in the contralto vocal range, the word is usually used only in the context of a female singer.
The bass singing voice has a vocal range that lies around the second E below middle C to the E above middle C (i.e., E–E).
 As with the contralto singing voice being the rarest female voice type, the bass voice is the rarest for males, and has the lowest vocal range of all voice types.
 However, the bass voice is determined not only by its vocal range, but also by its timbre, which tends to be darker than that of a baritone voice.
The contralto voice in opera and classical music has a range which typically lies between the F below middle C (F3) to two Fs above middle C (F5).
 In the lower and upper extremes, some contralto voices can sing from the E below middle C (E3) to two B♭ s above middle C (B♭ 5).
 The contralto voice has the lowest tessitura of the female voices and is noted for its rich and deep vocal timbre.
 True operatic contraltos are very rare.
 The following is a list of contralto singers who have regularly performed unamplified classical or operatic music in concert halls and/or opera houses.