When I've been following this thread, I couldn't help but notice certain patterns so I did a bit of analysis on the songs and artists
These are the most frequently posted songs with the number showing how many times they appeared
Blue Skies 6
Dream a Little Dream of Me 6
Love Is a Many Splendoured Thing 6
With a Song in My Heart 6
Baby, It's Cold Outside 5
Don't Stop Me Now 5
Always Look on the Bright Side of Life 4
Angels 4
Come Fly With Me 4
Rock Around the Clock 4
Ten Cents a Dance 4
34 songs appeared 3 times
As for Artists it's a bit harder, many songs have many versions particularly those in the great American Songbook. I chose the ones that seemed most iconic to me - in some case like New York, New York this is easy but to take an example With a Song In My Heart which occurred 6 times is harder - I went with Mario Lanza as it is the first version I remember. So for artists the count was for those with 10 or higher
Frank Sinatra 37
Ella Fitzgerald 34
The Beatles 28
Nat King Cole 21
Bing Crosby 18
Doris Day 13
Judy Garland 13
Abba 12
Andy Williams 10
Dean Martin 10
Mario Lanza 10
Queen 10
Note I had a section of traditional songs that didn't seem to align to anyone and there 20 of those
I posted this summary just over a year ago so I thought that someone might be interested in an updated version
The songs with more than 4 occurrences are
With a song in my heart 9
Dream a little dream of me 8
Always Look on the Bright Side of Life 6
Blue Skies 6
Don't Stop Me Now 6
Love Is a Many Splendoured Thing 6
The Power of Love 6*
Baby It's Cold Outside 5
Come Fly With Me 5
It's a Kind of Magic 5
It's a Lovely Day Today 5
No More the Fool 5
Rock Around the Clock 5
All You Need is Love 4
Amoreuse 4
Angels 4
Cry Me a River 4
Devil Gate Drive 4
Everybody Wants to Rule the World 4
Fools Rush In 4
For All We know 4
Hello 4
Homeward Bound 4
I Will Survive 4
In The Still of the Night 4
Moon River 4
On a Clear Day 4
Somewhere over the rainbow 4
Strangers in the Night 4
Ten Cents a Dance 4
Tonight 4
Walk on by 4
Wonderful World 4
* The Power of Love being 2 different songs 4 x the Frankie Goes to Hollywood version, and 2 of the Jennifer Rush - so far no Huey Lewis
Note it has been a bad year for Angels.
For artists
Frank Sinatra 55
Ella Fitzgerald 49
The Beatles 47
Trad. 34
Nat King Cole 28
Abba 24
Bing Crosby 24
Queen 23
Doris Day 22
Judy Garland 21
Simon and Garfunkel 18
Mario Lanza 15
Gene Kelly 14
Billie Holiday 13
Diana Ross and The Supremes 13
Fred Astaire 13
Andy Williams 12
Barbra Streisand 12
Louis Armstrong 12
Theme 12*
Dean Martin 11
Hymn 11
The Rolling Stones 11
Tony Bennett 11
Roy Orbison 10
Vera Lynn 10
Wings 10
* Tv Themes e.g. Happy Days
In addition to Paul McCartney having 47 appearances with the Beatles and 10 with Wings, he had 6 solo appearances and 3 duets.
Paul Simon has a further 7 solo appearances to go along with the 18 S & G.
Fred Astaire and Judy Garland additional 2 duets, and Gene Kelly an additional 2 as part of a trio