He also transmits report 45 with an authentic chain from al-Qāsim ibn Salman—whom Ibn Ḥibbān declared reliable—in which he said:
“The singer and the one for whom he sings are both cursed.”

Likewise, Ibn Naṣr relates in Qadr al-Ṣalāt, q 151/2, with a good chain from him:
“Music makes hypocrisy grow in the heart just as water makes crops grow, whereas remembrance (dhikr) makes faith grow in the heart just as water makes crops grow.”

Could al-Shaʿbī have uttered such statements merely out of personal inclination? May Allah guide you.

As for his remark, “it is unanimously agreed…,” its falsity has already been exposed above, so there is no need to prolong the rebuttal.