It's either called "The Instrument Song" or "The Orchestra"....
finally I found it!

The Instrument Song Austrian Folk

Children love singing this round as the classroom is divided
into five sections, each representing an instrument of the orchestra.
As each instrument is introduced, it is heard first as a solo, then joined
by the others that have already been heard to produce a harmonious
"orchestra."

"Violins"
The violins ringing like lovely singing.
The violins ringing like lovely song.

"Clarinets"
The clarinet, the clarinet
Goes doodle doodle doodle doodle det.
The clarinet, the clarinet
Goes doodle doodle doodle det.

"Trumpets"
The trumpet is braying,
Ta ta ta ta ta ta ta ta ta ta ta ta ta ta ta ta ta .

"Horns"
The horn, the horn
Awakes me at morn.
The horn, the horn
Awakes me at morn.

"Drums"
The drums playing two tones
They're always the same tones.
The drums playing two tones.
They're always the same.

The Orchestra [G – A]
1 The violin’s ringing like lovely singing. The violin’s ringing like lovely song
2 The trumpet is sounding ta ta ta- ta da da da ta ta ta Ta da da da ta ta ta

The trumpet is sounding ta ta ta- ta da da da ta ta ta Ta
3 The clarinet the clarinet goes doodle doodle doodle doodle det

The clarinet the clarinet goes doodle doodle doodle det
4 The drum it plays 2 tones and always the same tones

Five– one one – five five five five five one
5 The horn the horn awakes me at morn (2x)

Meg Ryan is attending a family party and the group gathers around a piano.
> Among other songs, they sing something about parts of an orchestra,
> imitating the sounds of the clarinet, the horn, and violin. I knew this
> song from years ago in school. Does it have a title? Where could I find
> it? Thanks!