Still fine, though no way the best.
The best portrayals of Abigaille, assumed daughter of Nabucco, came from two great Greek sopranos, Maria Callas and Elena Souliotis.
Callas recorded a live Nabucco in 1949 in Naples with Bechi, but the sound quality is outright horrific. Souliotis, however, did leave a wonderful recording with Tito Gobbi in the title role.
The present one, under a young Riccardo Muti starring Manuguerra in title role could have fared much better had Ghiaurov and Scotto been in better voices at the time of recording. As it is, both sounded underpowered and at times pale.
Manuguerra is perhaps the best performer in this recording.
And the conducting of Muti is only somewhere in the middle road. The great chorus of the Hebrews did not own the wonderful sound that it should have. The score should have much more drama and force than that realised by Muti.

Almost a Great Performance
Nabucco, Verdi's third opera, almost didn't get written. Verdi had a modest success with Oberto, his first opera, but his second one, Un Giorno di Regno was a dismal flop, closing after only one performance. Verdi, with a wife and two children was on the verge of chucking it all in when he was persuaded to read the libretto. The rest is history. The northern Italians, under Austrian domination, immediately identified with the oppressed Hebrews. Nabucco gave Verdi an international reputation and set him on his way to becoming the musical symbol of Italian nationalism. To this day he is Italy's iconic composer and the Hebrews' chorus, "Va pensiero" is an unofficial national anthem.

The story is complicated. The opera opens with the Hebrews in Solomon's Temple, lamenting their military defeat by the army of Nabucco, (Nebuchadnezzar), king of Babylon-- although they have managed to capture his younger daughter, Fenena. Zechariah, the Hebrew high priest, drags her in and exhorts the Hebrews to be valiant. Ismael, the Hebrew king's nephew, rushes in to inform all that Nabucco and his army are at the gates. Zechariah and the Hebrews rush off to do battle, leaving Fenena in the custody of Ismael. It turns out they are old lovers from when Ismael was the Hebrew ambassador to Babylon, and promptly sing of their love for each other. Abigail, Nabucco's elder daughter, rushes in with some Babylonian troops and offers to save the Hebrews if Ismael will return her love. He won't. Zechariah and the Hebrews come pouring back, defeated again, followed by Nabucco. Zechariah threatens to kill Femena unless Nabucco withdraws, but Ismael snatches the dagger from his hand. Nabucco orders the temple sacked, Abigail swears to exterminate the Jews, and Zechariah curses Ismael as a traitor to the Hebrews.

In part 2, set now in Babylon, Abigail has discovered a document that proves she isn't really Nabucco's daughter but a slave instead. Not happy, she vows vengeance on Ismael, Nabucco, Femena, the Hebrews, and the whole Babylonian kingdom. When the Babylonian high priest enters to report that Femena, whom Nabucco left as regent while he was away conquering other lands, is freeing the Hebrews, Abigail decides to seize the throne for herself and leaves. Zechariah enters, accompanied by the Hebrews and Ismael. The Hebrews continue to accuse Ismael of treachery, but Zechariah and his sister Anna point out that Ismael has in fact increased the population as he has converted Femena to Judaism. Abigail comes in with her cronies and demands the regent's crown from Femena, but before she can take power Nabucco returns and takes the crown, claiming now to be a god, not just a king. He is promptly struck by lightening and is struck mad. Abigail grabs the crown and proclaims herself ruler of Babylon.

Part 3 opens with Abigail on the throne exulting, about to sign the death warrant for the Hebrews. Nabucco comes in and Abigail taunts him as a coward. Nabucco, to prove otherwise, signs the Hebrews' death warrant, (which also means death for Femena.) He tells Abigail she is a slave, but Abigail destroys the document that proves that in front of him. She's happy, he's not. When the trumpet signaling the imminent execution of the Hewbrews sounds, Nabucco calls for his guards. They enter, but arrest him instead as he pleads for mercy. The scene shifts to the Hebrews, who awaiting execution sing of their misery (the famous 'va pensiero'.) Zechariah chides them and bids them be steadfast.

In Part 4, Nabucco awakes and from his window sees the Hebrews, including his daughter Femena, being lead off to execution. Horrified he tries to stop them, but discoveres he is locked in his room. In answer to his prayers, a loyal officer arrives with some soldiers to rescue him and help him regain his throne. Outside, the Hebrews are singing and praying, when Nabucco arrives and rescues them. Nabucco frees the Hebrews and tells them to go home and rebuild their temple. Abigail comes in dying (not clear why), confesses her guilt, begs forgivness, and dies as Zechariah leads everyone in prayer again. Heady stuff.

Renata Scotto sings the demanding role of Abigail. Scotto was considered by many to be the heir to Callas--a lyric soprano without a particularly beautiful voice who nevertheless rose to the top of her profession by hard work, developing an excellent technique coupled with superb artistry and interpretation. A master of bel canto, she began taking on heavier and more dramatic roles, so that by the late 70s she began to have trouble in the higher register, becoming screechy and wobbly. At the time of this recording in 1978, this problem was becoming only slightly evident.

Ismael is sung by Veriano Luchetti, who would have been a superstar but for the fact that he was a direct contemporary and competitor with Domingo, Pavarotti and Carreras. He has a very flexible and smooth voice with a nice tone quality, a large range, and perfectly placed sound. He wisely specialized in the more obscure Verdi tenor roles, like those in Nabucco, Attila, Macbeth, and Simon Boccanegra.

Femena is sung by the wonderful Russian mezzo Elena Obraztsova, who has an agile and powerful voice with a huge range. Zecharia is sung by the great Russian bass Nicolai Ghiaurov, who has a polished and very expressive voice, also with excellent interpretive skills. The title role of Nabucco is sung by Metropolitan Opera bass Matteo Manuguerra, who originally started as a tenor. He has a warm melifluous voice, although a little generic.

Ricardo Muti conducts the Philharmonia Orchestra (a recording orchestra made up of members of various London symphonies) and the Ambrosian Opera Chorus, (ditto from various London choruses), with his usual firm hand. The sound, which was remastered in 1986, is excellent.)

I only give it four stars because despite the superb cast, this version never really catches fire. The music is terrific and dramatic and exciting--but this recording, although with only a few faults, just doesn't thrill the way it should. However, given the price, it's an excellent option.

Amazing
It's amazing how different people find such different things in a work of art. Unlike the other reviewers here, I found Matteo Manuguerra's Nabucco to be the outstanding feature of this exceptional recording. I am listening to his "Dio di Guida!" as I'm writing this review, and though he died in 1998, his heart and soul are pouring forth from my sound system. He is the reason I recommend buying this recording. Each to his/her own I guess.

This is not meant as a criticism of anyone here as I found your thoughtful words very helpful, but I often find that reviews focus on technical excellence and performance dynamics above all. I like to concentrate on the emotional content and artistry of the performance (i.e. how it effects me). Sure, I don't want a "flat" when a "sharp" is scored, but imagine how far Callas or Bergonzi would have got if we measured their artistry with a frequency meter.

still the best Nabucco available
In my opinion Nabucco is really difficult work for singers especially the three of main roles / King Nabuccodonosor, hight priest Zacharia and of course Abigail/. Furthermore it must be difficult / it is not a digital recording !/ to coop such amount of music and choruses in the recording / - the similar problem as Aida, Turandot etc.
All these difficult aspects are mastered here excellently.
The worst of the soloist is Ghiaurov, his voice really sounds tired here, but still is well acceptable. Manuguerra and Scotto perform the best recorded Nabucco and Abigail available. Both
their solo and duets are vivid, dramatic and real.
Muti conducts very well and choruses and orchestra sound absolutely perfect.
A lot of beauty for a very low price !
The four stars only ? Yes, Ghiaurov and Obraztsova would have been casted better, I think we had more eligible meyyo and bass at that time.

Scotto is not to be missed
I agree with those who find Manuguerra just a little boring, it's not a bad performance, but pales next to Scotto's magnificent Abigaile. Muti conducts very well, and he makes more of the Va Pensiero than Gardelli or Sinopoli. Forced to choose I would opt for this recording over the DECCA and the DG, it's just a pity that Renato Bruson was not chosen for the title role.