Nasheed refers to:
Rhythmic chanting of poetry
Usually done in a melodious tone
Sometimes accompanied by clapping, hand-beating, or musical instruments
Often promoted today as Islamic songs
Nasheeds were not part of the worship or regular practice of the Prophet ﷺ or his Companions.
They existed only as occasional poetry recitations without musical tones, without rhythms, and without making them acts of devotion.

2. الأدلة الشرعية الأساسية
(1) النهي عن المعازف والأصوات المطربة
The Prophet ﷺ said:
« لَيَكُونَنَّ مِنْ أُمَّتِي أَقْوَامٌ يَسْتَحِلُّونَ الحِرَ وَالحَرِيرَ وَالخَمْرَ وَالمَعَازِفَ »
There will be among my Ummah people who will regard as permissible: fornication, silk, alcohol, and musical instruments.
Reference: Saheeh al-Bukhari: 5590
This hadith is the foundation for the prohibition of music and musical-style chanting.
(2) الشعر مباح بضوابط
Poetry itself is allowed when:
Its content is good
It does not distract from obligations
It is not recited in a musical manner resembling singing
The Prophet ﷺ said:
« إِنَّ مِنَ الشِّعْرِ لَحِكْمَةً »
Indeed, some poetry contains wisdom.
Reference: Saheeh al-Bukhari: 6145
This proves permissibility of simple poetry, not singing or musical rhythms.

3. حال السلف مع الأناشيد

1. The Salaf did NOT use nasheeds as worship, reminders, or da'wah.
They recited poetry occasionally, in normal speech patterns, without melody.

2. They warned against singing-like chanting, as it is from the characteristics of the people of falsehood.

4. أقوال السلف والعلماء المتقدمين

Imam Ahmad رحمه الله
He said:
الغناء ينبت النفاق في القلب
Singing causes hypocrisy to grow in the heart.
Reference: As-Sunnah by al-Khallal: 3/493
When asked about people gathering to chant nasheeds (al-inshad), he disliked it and warned that it resembles the practices of innovators.

Al-Fudayl ibn ‘Iyaad رحمه الله
He said:
الإنشاد بدعة
Chanting (inshad) is a bid'ah.
Reference: Talbees Iblees: Ibn al-Jawzi, p. 244
He meant rhythmic chanting in a devotional context, not simple poetry.

Imam al-Shafi’i رحمه الله
He said:
خلفت ببغداد شيئا أحدثته الزنادقة يسمونه التغبير يشغلون به الناس عن القرآن
I left behind in Baghdad something newly introduced by the heretics which they call at-taghbeer (rhythmic chanting). They use it to distract people from the Qur'an.
Reference: Talbees Iblees: p. 232
This is a direct criticism of early forms of nasheeds.

Ibn Taymiyyah رحمه الله
He said:
الإنشاد المشتمل على ترقيق القلوب بدعة لم يفعله السلف
Emotional chanting meant to soften hearts is a bid'ah that was not practiced by the Salaf.
Reference: Majmoo al-Fatawa: 11/632
He also said nasheeds are allowed only as occasional poetry, without rhythm, melody, or taking them as a religious practice.

Ibn al-Qayyim رحمه الله
He wrote:
استبدلوا بسماع القرآن سماع القصائد
They replaced listening to the Qur'an with listening to poetic songs.
Reference: Ighaathat al-Lahfaan: 1/361
He warned this leads the heart away from the Qur'an.